View Source Explorer.Series (Explorer v0.8.1)

The Series struct and API.

A series can be of the following data types:

  • :binary - Binaries (sequences of bytes)
  • :boolean - Boolean
  • :category - Strings but represented internally as integers
  • :date - Date type that unwraps to Elixir.Date
  • {:datetime, precision} - DateTime type with millisecond/microsecond/nanosecond precision that unwraps to Elixir.NaiveDateTime
  • {:duration, precision} - Duration type with millisecond/microsecond/nanosecond precision that unwraps to Explorer.Duration
  • {:f, size} - a 64-bit or 32-bit floating point number
  • {:s, size} - a 8-bit or 16-bit or 32-bit or 64-bit signed integer number.
  • {:u, size} - a 8-bit or 16-bit or 32-bit or 64-bit unsigned integer number.
  • :null - nils exclusively
  • :string - UTF-8 encoded binary
  • :time - Time type that unwraps to Elixir.Time
  • {:list, dtype} - A recursive dtype that can store lists. Examples: {:list, :boolean} or a nested list dtype like {:list, {:list, :boolean}}.
  • {:struct, [{key, dtype}]} - A recursive dtype that can store Arrow/Polars structs (not to be confused with Elixir's struct). This type unwraps to Elixir maps with string keys. Examples: {:struct, [{"a", :string}]} or a nested struct dtype like {:struct, [{"a", {:struct, [{"b", :string}]}}]}.

When passing a dtype as argument, aliases are supported for convenience and compatibility with the Elixir ecosystem:

  • All numeric dtypes (signed integer, unsigned integer, and floats) can be specified as an atom in the form of :s32, :u8, :f32 and o son
  • The atom :float as an alias for {:f, 64} to mirror Elixir's floats
  • The atom :integer as an alias for {:s, 64} to mirror Elixir's integers

A series must consist of a single data type only. Series may have nil values in them. The series dtype can be retrieved via the dtype/1 function or directly accessed as series.dtype. A series.name field is also available, but it is always nil unless the series is retrieved from a dataframe.

Many functions only apply to certain dtypes. These functions may appear on distinct categories on the sidebar. Other functions may work on several datatypes, such as comparison functions. In such cases, a "Supported dtypes" section will be available in the function documentation.

Creating series

Series can be created using from_list/2, from_binary/3, and friends:

Series can be made of numbers:

iex> Explorer.Series.from_list([1, 2, 3])
#Explorer.Series<
  Polars[3]
  s64 [1, 2, 3]
>

Series are nullable, so you may also include nils:

iex> Explorer.Series.from_list([1.0, nil, 2.5, 3.1])
#Explorer.Series<
  Polars[4]
  f64 [1.0, nil, 2.5, 3.1]
>

Any of the dtypes above are supported, such as strings:

iex> Explorer.Series.from_list(["foo", "bar", "baz"])
#Explorer.Series<
  Polars[3]
  string ["foo", "bar", "baz"]
>

Casting numeric series (type promotion)

Series of integers and floats are automatically cast when executing certain operations. For example, adding a series of s64 with f64 will return a list of f64.

Numeric casting works like this:

  • when working with the same numeric type but of different precisions, the higher precision wins

  • when working with unsigned integers and signed integers, unsigned integers are cast to signed integers using double of its precision (maximum of 64 bits)

  • when working with integers and floats, integers are always cast floats, keep the floating number precision

Series queries

DataFrames have named columns, so their queries use column names as variables:

iex> require Explorer.DataFrame
iex> df = Explorer.DataFrame.new(col_name: [1, 2, 3])
iex> Explorer.DataFrame.filter(df, col_name > 2)
#Explorer.DataFrame<
  Polars[1 x 1]
  col_name s64 [3]
>

Series have no named columns (a series constitutes a single column, so no name is required). This means their queries can't use column names as variables. Instead, series queries use the special _ variable like so:

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.filter(s, _ > 2)
#Explorer.Series<
  Polars[1]
  s64 [3]
>

Summary

Functions: Conversion

Builds a series of dtype from binary.

Creates a new series from a list.

Replaces the contents of the given series by the one given in a tensor or list.

Returns a series as a fixed-width binary.

Converts a series to an enumerable.

Returns a series as a list of fixed-width binaries.

Converts a series to a list.

Functions: Aggregation

Returns if all the values in a boolean series are true.

Returns if any of the values in a boolean series are true.

Gets the index of the maximum value of the series.

Gets the index of the minimum value of the series.

Compute the correlation between two series.

Counts the number of non-nil elements in a series.

Compute the covariance between two series.

Bins values into discrete values.

Creates a new dataframe with unique values and the frequencies of each.

Gets the maximum value of the series.

Gets the mean value of the series.

Gets the median value of the series.

Gets the minimum value of the series.

Gets the most common value(s) of the series.

Returns the number of unique values in the series.

Counts the number of nil elements in a series.

Reduce this Series to the product value.

Bins values into discrete values base on their quantiles.

Gets the given quantile of the series.

Compute the sample skewness of a series.

Gets the standard deviation of the series.

Gets the sum of the series.

Gets the variance of the series.

Functions: Element-wise

Gets the series absolute values.

Adds right to left, element-wise.

Checks equality between two entire series.

Returns a boolean mask of left and right, element-wise.

Cast the series to another type.

Categorise a series of integers or strings according to categories.

Clip (or clamp) the values in a series.

Finds the first non-missing element at each position.

Finds the first non-missing element at each position.

Divides left by right, element-wise.

Returns boolean mask of left == right, element-wise.

Calculates the exponential of all elements.

Picks values based on an Explorer.Query.

Filters a series with a callback function.

Returns boolean mask of left > right, element-wise.

Returns boolean mask of left >= right, element-wise.

Checks if each element of the series in the left exists in the series on the right, returning a boolean mask.

Returns a mask of nil values.

Returns a mask of not nil values.

Returns boolean mask of left < right, element-wise.

Returns boolean mask of left <= right, element-wise.

Calculates the natural logarithm.

Calculates the logarithm on a given base.

Maps values based on an Explorer.Query.

Maps a series with a callback function.

Filters a series with a mask.

Multiplies left and right, element-wise.

Negate the elements of a boolean series.

Returns boolean mask of left != right, element-wise.

Returns a boolean mask of left or right, element-wise.

Returns a boolean mask with true where the 'peaks' (series max or min, default max) are.

Raises a numeric series to the power of the exponent.

Element-wise integer division.

Assign ranks to data with appropriate handling of tied values.

Computes the remainder of an element-wise integer division.

Returns a series of indexes for each item (row) in the series, starting from 0.

Returns a series from two series, based on a predicate.

Converts a datetime series to a string series.

Converts a string series to a datetime series with a given format_string.

Subtracts right from left, element-wise.

Returns an Explorer.Series where each element is the result of invoking fun on each corresponding element of series.

Functions: Datetime ops

Returns a day-of-week number starting from Monday = 1. (ISO 8601 weekday number)

Returns the day-of-year number starting from 1.

Returns the hour number from 0 to 23.

Returns the minute number from 0 to 59.

Returns the month number starting from 1. The return value ranges from 1 to 12.

Returns the second number from 0 to 59.

Returns the week-of-year number.

Returns the year number in the calendar date.

Functions: Float ops

Computes the the arccosine of a number. The resultant series is going to be of dtype {:f, 64}, in radians, with values between 0 and pi.

Computes the the arcsine of a number. The resultant series is going to be of dtype {:f, 64}, in radians, with values between -pi/2 and pi/2.

Computes the the arctangent of a number. The resultant series is going to be of dtype {:f, 64}, in radians, with values between -pi/2 and pi/2.

Ceil floating point series to highest integers smaller or equal to the float value.

Computes the the cosine of a number (in radians). The resultant series is going to be of dtype {:f, 64}, with values between 1 and -1.

Floor floating point series to lowest integers smaller or equal to the float value.

Returns a mask of finite values.

Returns a mask of infinite values.

Returns a mask of nan values.

Round floating point series to given decimal places.

Computes the the sine of a number (in radians). The resultant series is going to be of dtype {:f, 64}, with values between 1 and -1.

Computes the tangent of a number (in radians). The resultant series is going to be of dtype {:f, 64}.

Functions: String ops

Detects whether a string contains a substring.

Converts all characters to lowercase.

Decodes a string series containing valid JSON according to dtype.

Extracts a string series using a json_path from a series.

Returns a string series where all leading Unicode whitespaces have been removed.

Returns a string series where all leading examples of the provided string have been removed.

Replaces all occurences of pattern with replacement in string series.

Returns a string series where all trailing Unicode whitespaces have been removed.

Returns a string series where all trailing examples of the provided string have been removed.

Split the string by a substring.

Returns a string series where all leading and trailing Unicode whitespaces have been removed.

Returns a string series where all leading and trailing examples of the provided string have been removed.

Returns a string sliced from the offset to the end of the string, supporting negative indexing

Returns a string sliced from the offset to the length provided, supporting negative indexing

Converts all characters to uppercase.

Functions: List ops

Join all string items in a sublist and place a separator between them.

Calculates the length of each list in a list series.

Checks for the presence of a value in a list series.

Functions: Struct ops

Extracts a field from a struct series

Functions: Introspection

Return a series with the category names of a categorical series.

Returns the data type of the series.

Returns the type of the underlying fixed-width binary representation.

Returns the number of elements in the series.

Functions: Shape

Returns the indices that would sort the series.

Returns the value of the series at the given index.

Takes every nth value in this series, returned as a new series.

Concatenate one or more series.

Concatenate two series.

Returns the unique values of the series.

Returns the first element of the series.

Returns a string series with all values concatenated.

Returns the first N elements of the series.

Returns the last element of the series.

Reverses the series order.

Returns a random sample of the series.

Shifts series by offset with nil values.

Change the elements order randomly.

Slices the elements at the given indices as a new series.

Returns a slice of the series, with size elements starting at offset.

Sorts the series.

Sorts the series based on an expression.

Sorts the series based on a callback that returns a lazy series.

Returns the last N elements of the series.

Returns the unique values of the series, but does not maintain order.

Functions: Window

Calculates the cumulative maximum of the series.

Calculates the cumulative minimum of the series.

Calculates the cumulative product of the series.

Calculates the cumulative sum of the series.

Calculate the exponentially weighted moving average, given smoothing factor alpha.

Calculate the exponentially weighted moving standard deviation, given smoothing factor alpha.

Calculate the exponentially weighted moving variance, given smoothing factor alpha.

Fill missing values with the given strategy. If a scalar value is provided instead of a strategy atom, nil will be replaced with that value. It must be of the same dtype as the series.

Calculate the rolling max, given a window size and optional list of weights.

Calculate the rolling mean, given a window size and optional list of weights.

Calculate the rolling median, given a window size and optional list of weights.

Calculate the rolling min, given a window size and optional list of weights.

Calculate the rolling standard deviation, given a window size and optional list of weights.

Calculate the rolling sum, given a window size and optional list of weights.

Functions

to_date(series) deprecated
to_time(series) deprecated

Functions: Conversion

Link to this function

from_binary(binary, dtype, opts \\ [])

View Source
@spec from_binary(
  binary(),
  :boolean
  | :date
  | :time
  | datetime_dtype()
  | duration_dtype()
  | float_dtype()
  | float_dtype_alias()
  | integer_dtype_alias()
  | signed_integer_dtype()
  | unsigned_integer_dtype(),
  keyword()
) :: t()

Builds a series of dtype from binary.

All binaries must be in native endianness.

Options

  • :backend - The backend to allocate the series on.

Examples

Integers and floats follow their native encoding:

iex> Explorer.Series.from_binary(<<1.0::float-64-native, 2.0::float-64-native>>, {:f, 64})
#Explorer.Series<
  Polars[2]
  f64 [1.0, 2.0]
>

iex> Explorer.Series.from_binary(<<-1::signed-64-native, 1::signed-64-native>>, :integer)
#Explorer.Series<
  Polars[2]
  s64 [-1, 1]
>

Booleans are unsigned integers:

iex> Explorer.Series.from_binary(<<1, 0, 1>>, :boolean)
#Explorer.Series<
  Polars[3]
  boolean [true, false, true]
>

Dates are encoded as s32 representing days from the Unix epoch (1970-01-01):

iex> binary = <<-719162::signed-32-native, 0::signed-32-native, 6129::signed-32-native>>
iex> Explorer.Series.from_binary(binary, :date)
#Explorer.Series<
  Polars[3]
  date [0001-01-01, 1970-01-01, 1986-10-13]
>

Times are encoded as s64 representing nanoseconds from midnight:

iex> binary = <<0::signed-64-native, 86399999999000::signed-64-native>>
iex> Explorer.Series.from_binary(binary, :time)
#Explorer.Series<
  Polars[2]
  time [00:00:00.000000, 23:59:59.999999]
>

Datetimes are encoded as s64 representing microseconds from the Unix epoch (1970-01-01):

iex> binary = <<0::signed-64-native, 529550625987654::signed-64-native>>
iex> Explorer.Series.from_binary(binary, {:datetime, :microsecond})
#Explorer.Series<
  Polars[2]
  datetime[μs] [1970-01-01 00:00:00.000000, 1986-10-13 01:23:45.987654]
>
Link to this function

from_list(list, opts \\ [])

View Source
@spec from_list(list :: list(), opts :: Keyword.t()) :: t()

Creates a new series from a list.

The list must consist of a single data type and nils. It is possible to have a list of only nil values. In this case, the list will have the :dtype of :null.

Options

  • :backend - The backend to allocate the series on.
  • :dtype - Cast the series to a given :dtype. By default this is nil, which means that Explorer will infer the type from the values in the list. See the module docs for the list of valid dtypes and aliases.

Examples

Explorer will infer the type from the values in the list. Integers are always treated as s64 and floats are always treated as f64:

iex> Explorer.Series.from_list([1, 2, 3])
#Explorer.Series<
  Polars[3]
  s64 [1, 2, 3]
>
iex> Explorer.Series.from_list([1.0, 2.0, 3.0])
#Explorer.Series<
  Polars[3]
  f64 [1.0, 2.0, 3.0]
>

Series are nullable, so you may also include nils:

iex> Explorer.Series.from_list([1.0, nil, 2.5, 3.1])
#Explorer.Series<
  Polars[4]
  f64 [1.0, nil, 2.5, 3.1]
>

A mix of integers and floats will be cast to a float:

iex> Explorer.Series.from_list([1, 2.0])
#Explorer.Series<
  Polars[2]
  f64 [1.0, 2.0]
>

Floats series can accept NaN, Inf, and -Inf values:

iex> Explorer.Series.from_list([1.0, 2.0, :nan, 4.0])
#Explorer.Series<
  Polars[4]
  f64 [1.0, 2.0, NaN, 4.0]
>

iex> Explorer.Series.from_list([1.0, 2.0, :infinity, 4.0])
#Explorer.Series<
  Polars[4]
  f64 [1.0, 2.0, Inf, 4.0]
>

iex> Explorer.Series.from_list([1.0, 2.0, :neg_infinity, 4.0])
#Explorer.Series<
  Polars[4]
  f64 [1.0, 2.0, -Inf, 4.0]
>

Trying to create an empty series or a series of nils will, by default, result in a series of :null type:

iex> Explorer.Series.from_list([])
#Explorer.Series<
  Polars[0]
  null []
>
iex> Explorer.Series.from_list([nil, nil])
#Explorer.Series<
  Polars[2]
  null [nil, nil]
>

A list of Date, Time, NaiveDateTime, and Explorer.Duration structs are also supported, and they will become series with the respective dtypes: :date, :time, {:datetime, :microsecond}, and {:duration, precision}. For example:

iex> Explorer.Series.from_list([~D[0001-01-01], ~D[1970-01-01], ~D[1986-10-13]])
#Explorer.Series<
  Polars[3]
  date [0001-01-01, 1970-01-01, 1986-10-13]
>

You can specify the desired dtype for a series with the :dtype option.

iex> Explorer.Series.from_list([nil, nil], dtype: :integer)
#Explorer.Series<
  Polars[2]
  s64 [nil, nil]
>

iex> Explorer.Series.from_list([1, nil], dtype: :string)
#Explorer.Series<
  Polars[2]
  string ["1", nil]
>

iex> Explorer.Series.from_list([1, 2], dtype: :f32)
#Explorer.Series<
  Polars[2]
  f32 [1.0, 2.0]
>

iex> Explorer.Series.from_list([1, nil, 2], dtype: :float)
#Explorer.Series<
  Polars[3]
  f64 [1.0, nil, 2.0]
>

The dtype option is particulary important if a :binary series is desired, because by default binary series will have the dtype of :string:

iex> Explorer.Series.from_list([<<228, 146, 51>>, <<42, 209, 236>>], dtype: :binary)
#Explorer.Series<
  Polars[2]
  binary [<<228, 146, 51>>, <<42, 209, 236>>]
>

A series mixing UTF8 strings and binaries is possible:

iex> Explorer.Series.from_list([<<228, 146, 51>>, "Elixir"], dtype: :binary)
#Explorer.Series<
  Polars[2]
  binary [<<228, 146, 51>>, "Elixir"]
>

Another option is to create a categorical series from a list of strings:

iex> Explorer.Series.from_list(["EUA", "Brazil", "Poland"], dtype: :category)
#Explorer.Series<
  Polars[3]
  category ["EUA", "Brazil", "Poland"]
>

It is possible to create a series of :datetime from a list of microseconds since Unix Epoch.

iex> Explorer.Series.from_list([1649883642 * 1_000 * 1_000], dtype: {:datetime, :microsecond})
#Explorer.Series<
  Polars[1]
  datetime[μs] [2022-04-13 21:00:42.000000]
>

It is possible to create a series of :time from a list of nanoseconds since midnight.

iex> Explorer.Series.from_list([123 * 1_000 * 1_000 * 1_000], dtype: :time)
#Explorer.Series<
  Polars[1]
  time [00:02:03.000000]
>

Mixing non-numeric data types will raise an ArgumentError:

iex> Explorer.Series.from_list([1, "a"])
** (ArgumentError) the value "a" does not match the inferred dtype {:s, 64}
Link to this function

from_tensor(tensor, opts \\ [])

View Source
@spec from_tensor(tensor :: Nx.Tensor.t(), opts :: Keyword.t()) :: t()

Converts a Nx.Tensor.t/0 to a series.

Warning

Nx is an optional dependency. You will need to ensure it's installed to use this function.

Options

  • :backend - The backend to allocate the series on.

  • :dtype - The dtype of the series that must match the underlying tensor type.

    The series can have a different dtype if the tensor is compatible with it. For example, a tensor of {:u, 8} can represent a series of :boolean dtype.

    Here are the list of compatible tensor types and dtypes:

    • {:u, 8} tensor as a :boolean series.
    • {:s, 32} tensor as a :date series.
    • {:s, 64} tensor as a :time series.
    • {:s, 64} tensor as a {:datetime, unit} or {:duration, unit} series.

Examples

Integers and floats:

iex> tensor = Nx.tensor([1, 2, 3])
iex> Explorer.Series.from_tensor(tensor)
#Explorer.Series<
  Polars[3]
  s64 [1, 2, 3]
>

iex> tensor = Nx.tensor([1.0, 2.0, 3.0], type: :f64)
iex> Explorer.Series.from_tensor(tensor)
#Explorer.Series<
  Polars[3]
  f64 [1.0, 2.0, 3.0]
>

iex> tensor = Nx.tensor([1, 0, 1], type: :u8)
iex> Explorer.Series.from_tensor(tensor)
#Explorer.Series<
  Polars[3]
  u8 [1, 0, 1]
>

iex> tensor = Nx.tensor([-719162, 0, 6129], type: :s32)
iex> Explorer.Series.from_tensor(tensor)
#Explorer.Series<
  Polars[3]
  s32 [-719162, 0, 6129]
>

Booleans can be read from a tensor of {:u, 8} type if the dtype is explicitly given:

iex> tensor = Nx.tensor([1, 0, 1], type: :u8)
iex> Explorer.Series.from_tensor(tensor, dtype: :boolean)
#Explorer.Series<
  Polars[3]
  boolean [true, false, true]
>

Times are signed 64-bit representing nanoseconds from midnight and therefore must have their dtype explicitly given:

iex> tensor = Nx.tensor([0, 86399999999000])
iex> Explorer.Series.from_tensor(tensor, dtype: :time)
#Explorer.Series<
  Polars[2]
  time [00:00:00.000000, 23:59:59.999999]
>

Datetimes are signed 64-bit and therefore must have their dtype explicitly given:

iex> tensor = Nx.tensor([0, 529550625987654])
iex> Explorer.Series.from_tensor(tensor, dtype: {:datetime, :microsecond})
#Explorer.Series<
  Polars[2]
  datetime[μs] [1970-01-01 00:00:00.000000, 1986-10-13 01:23:45.987654]
>
Link to this function

replace(series, tensor_or_list)

View Source
@spec replace(t(), Nx.Tensor.t() | list()) :: t()

Replaces the contents of the given series by the one given in a tensor or list.

The new series will have the same dtype and backend as the current series, but the size may not necessarily match.

Tensor examples

iex> s = Explorer.Series.from_list([0, 1, 2])
iex> Explorer.Series.replace(s, Nx.tensor([1, 2, 3]))
#Explorer.Series<
  Polars[3]
  s64 [1, 2, 3]
>

This is particularly useful for categorical columns:

iex> s = Explorer.Series.from_list(["foo", "bar", "baz"], dtype: :category)
iex> Explorer.Series.replace(s, Nx.tensor([2, 1, 0]))
#Explorer.Series<
  Polars[3]
  category ["baz", "bar", "foo"]
>

List examples

Similar to tensors, we can also replace by lists:

iex> s = Explorer.Series.from_list([0, 1, 2])
iex> Explorer.Series.replace(s, [1, 2, 3, 4, 5])
#Explorer.Series<
  Polars[5]
  s64 [1, 2, 3, 4, 5]
>

The same considerations as above apply.

@spec to_binary(series :: t()) :: binary()

Returns a series as a fixed-width binary.

This is a shortcut around to_iovec/1. If possible, prefer to use to_iovec/1 as that avoids copying binaries.

Examples

iex> series = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.to_binary(series)
<<1::signed-64-native, 2::signed-64-native, 3::signed-64-native>>

iex> series = Explorer.Series.from_list([true, false, true])
iex> Explorer.Series.to_binary(series)
<<1, 0, 1>>
@spec to_enum(series :: t()) :: Enumerable.t()

Converts a series to an enumerable.

The enumerable will lazily traverse the series.

Warning

You must avoid converting a series to enum, as that will copy the whole series in memory as you traverse it. Prefer to use the operations in this module rather than the ones in Enum whenever possible, as this module is optimized for large series.

Examples

iex> series = Explorer.Series.from_list([1, 2, 3])
iex> series |> Explorer.Series.to_enum() |> Enum.to_list()
[1, 2, 3]
@spec to_iovec(series :: t()) :: [binary()]

Returns a series as a list of fixed-width binaries.

An io vector (iovec) is the Erlang VM term for a flat list of binaries. This is typically a reference to the in-memory representation of the series. If the whole series in contiguous in memory, then the list will have a single element. All binaries are in native endianness.

This operation fails if the series has nil values. Use fill_missing/1 to handle them accordingly.

To retrieve the type of the underlying io vector, use iotype/1. To convert an iovec to a binary, you can use IO.iodata_to_binary/1.

Examples

Integers and floats follow their native encoding:

iex> series = Explorer.Series.from_list([-1, 0, 1])
iex> Explorer.Series.to_iovec(series)
[<<-1::signed-64-native, 0::signed-64-native, 1::signed-64-native>>]

iex> series = Explorer.Series.from_list([1.0, 2.0, 3.0])
iex> Explorer.Series.to_iovec(series)
[<<1.0::float-64-native, 2.0::float-64-native, 3.0::float-64-native>>]

Booleans are encoded as 0 and 1:

iex> series = Explorer.Series.from_list([true, false, true])
iex> Explorer.Series.to_iovec(series)
[<<1, 0, 1>>]

Dates are encoded as s32 representing days from the Unix epoch (1970-01-01):

iex> series = Explorer.Series.from_list([~D[0001-01-01], ~D[1970-01-01], ~D[1986-10-13]])
iex> Explorer.Series.to_iovec(series)
[<<-719162::signed-32-native, 0::signed-32-native, 6129::signed-32-native>>]

Times are encoded as s64 representing nanoseconds from midnight:

iex> series = Explorer.Series.from_list([~T[00:00:00.000000], ~T[23:59:59.999999]])
iex> Explorer.Series.to_iovec(series)
[<<0::signed-64-native, 86399999999000::signed-64-native>>]

Datetimes are encoded as s64 representing their precision from the Unix epoch (1970-01-01):

iex> series = Explorer.Series.from_list([~N[0001-01-01 00:00:00], ~N[1970-01-01 00:00:00], ~N[1986-10-13 01:23:45.987654]])
iex> Explorer.Series.to_iovec(series)
[<<-62135596800000000::signed-64-native, 0::signed-64-native, 529550625987654::signed-64-native>>]

The operation raises for binaries and strings, as they do not provide a fixed-width binary representation:

iex> s = Explorer.Series.from_list(["a", "b", "c", "b"])
iex> Explorer.Series.to_iovec(s)
** (ArgumentError) cannot convert series of dtype :string into iovec

However, if appropriate, you can convert them to categorical types, which will then return the index of each category:

iex> series = Explorer.Series.from_list(["a", "b", "c", "b"], dtype: :category)
iex> Explorer.Series.to_iovec(series)
[<<0::unsigned-32-native, 1::unsigned-32-native, 2::unsigned-32-native, 1::unsigned-32-native>>]
@spec to_list(series :: t()) :: list()

Converts a series to a list.

Warning

You must avoid converting a series to list, as that requires copying the whole series in memory. Prefer to use the operations in this module rather than the ones in Enum whenever possible, as this module is optimized for large series.

Examples

iex> series = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.to_list(series)
[1, 2, 3]
Link to this function

to_tensor(series, tensor_opts \\ [])

View Source
@spec to_tensor(series :: t(), tensor_opts :: Keyword.t()) :: Nx.Tensor.t()

Converts a series to a Nx.Tensor.t/0.

Note that Explorer.Series are automatically converted to tensors when passed to numerical definitions. The tensor type is given by iotype/1.

Warning

Nx is an optional dependency. You will need to ensure it's installed to use this function.

Options

  • :backend - the Nx backend to allocate the tensor on

Examples

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.to_tensor(s)
#Nx.Tensor<
  s64[3]
  [1, 2, 3]
>

iex> s = Explorer.Series.from_list([true, false, true])
iex> Explorer.Series.to_tensor(s)
#Nx.Tensor<
  u8[3]
  [1, 0, 1]
>

Functions: Aggregation

@spec all?(series :: t()) :: boolean()

Returns if all the values in a boolean series are true.

Supported dtypes

  • :boolean

Examples

iex> s = Series.from_list([true, true, true])
iex> Series.all?(s)
true

iex> s = Series.from_list([true, false, true])
iex> Series.all?(s)
false

iex> s = Series.from_list([1, 2, 3])
iex> Series.all?(s)
** (ArgumentError) Explorer.Series.all?/1 not implemented for dtype {:s, 64}. Valid dtype is :boolean

An empty series will always return true:

iex> s = Series.from_list([], dtype: :boolean)
iex> Series.all?(s)
true

Opposite to Elixir but similar to databases, nil values are ignored:

iex> s = Series.from_list([nil, true, true])
iex> Series.all?(s)
true

iex> s = Series.from_list([nil, nil, nil], dtype: :boolean)
iex> Series.all?(s)
true
@spec any?(series :: t()) :: boolean()

Returns if any of the values in a boolean series are true.

Supported dtypes

  • :boolean

Examples

iex> s = Series.from_list([true, true, true])
iex> Series.any?(s)
true

iex> s = Series.from_list([true, false, true])
iex> Series.any?(s)
true

iex> s = Series.from_list([1, 2, 3])
iex> Series.any?(s)
** (ArgumentError) Explorer.Series.any?/1 not implemented for dtype {:s, 64}. Valid dtype is :boolean

An empty series will always return false:

iex> s = Series.from_list([], dtype: :boolean)
iex> Series.any?(s)
false

Opposite to Elixir but similar to databases, nil values are ignored:

iex> s = Series.from_list([nil, true, true])
iex> Series.any?(s)
true

iex> s = Series.from_list([nil, nil, nil], dtype: :boolean)
iex> Series.any?(s)
false
@spec argmax(series :: t()) :: number() | non_finite() | nil

Gets the index of the maximum value of the series.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :date
  • :time
  • :datetime
  • :duration

Examples

iex> s = Explorer.Series.from_list([1, 2, nil, 3])
iex> Explorer.Series.argmax(s)
3

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, 3.0])
iex> Explorer.Series.argmax(s)
3

iex> s = Explorer.Series.from_list([~D[2021-01-01], ~D[1999-12-31]])
iex> Explorer.Series.argmax(s)
0

iex> s = Explorer.Series.from_list([~N[2021-01-01 00:00:00], ~N[1999-12-31 00:00:00]])
iex> Explorer.Series.argmax(s)
0

iex> s = Explorer.Series.from_list([~T[00:02:03.000212], ~T[00:05:04.000456]])
iex> Explorer.Series.argmax(s)
1

iex> s = Explorer.Series.from_list([], dtype: :integer)
iex> Explorer.Series.argmax(s)
nil

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.argmax(s)
** (ArgumentError) Explorer.Series.argmax/1 not implemented for dtype :string. Valid dtypes are :date, :time, {:datetime, :microsecond}, {:datetime, :millisecond}, {:datetime, :nanosecond}, {:duration, :microsecond}, {:duration, :millisecond}, {:duration, :nanosecond}, {:f, 32}, {:f, 64}, {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
@spec argmin(series :: t()) :: number() | non_finite() | nil

Gets the index of the minimum value of the series.

Note that nil is ignored. In case an empty list or a series whose all elements are nil is used, the result will be nil.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :date
  • :time
  • :datetime
  • :duration

Examples

iex> s = Explorer.Series.from_list([1, 2, nil, 3])
iex> Explorer.Series.argmin(s)
0

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, 3.0])
iex> Explorer.Series.argmin(s)
0

iex> s = Explorer.Series.from_list([~D[2021-01-01], ~D[1999-12-31]])
iex> Explorer.Series.argmin(s)
1

iex> s = Explorer.Series.from_list([~N[2021-01-01 00:00:00], ~N[1999-12-31 00:00:00]])
iex> Explorer.Series.argmin(s)
1

iex> s = Explorer.Series.from_list([~T[00:02:03.000212], ~T[00:05:04.000456]])
iex> Explorer.Series.argmin(s)
0

iex> s = Explorer.Series.from_list([], dtype: :integer)
iex> Explorer.Series.argmin(s)
nil

iex> s = Explorer.Series.from_list([nil], dtype: :integer)
iex> Explorer.Series.argmin(s)
nil

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.argmin(s)
** (ArgumentError) Explorer.Series.argmin/1 not implemented for dtype :string. Valid dtypes are :date, :time, {:datetime, :microsecond}, {:datetime, :millisecond}, {:datetime, :nanosecond}, {:duration, :microsecond}, {:duration, :millisecond}, {:duration, :nanosecond}, {:f, 32}, {:f, 64}, {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
Link to this function

correlation(left, right, opts \\ [])

View Source
@spec correlation(
  left :: t() | number(),
  right :: t() | number(),
  opts :: Keyword.t()
) :: float() | non_finite() | nil

Compute the correlation between two series.

The parameter ddof refers to the 'delta degrees of freedom' - the divisor used in the correlation calculation. Defaults to 1.

The parameter :method refers to the correlation method. The following methods are available:

  • :pearson : Standard correlation coefficient. (default)
  • :spearman : Spearman rank correlation.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s1 = Series.from_list([1, 8, 3])
iex> s2 = Series.from_list([4, 5, 2])
iex> Series.correlation(s1, s2)
0.5447047794019219

Counts the number of non-nil elements in a series.

See also:

  • count_nil/1 - counts only the nil elements.
  • size/1 - counts all elements.

Examples

Without nil:

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.count(s)
3

With nil:

iex> s = Explorer.Series.from_list(["a", nil, "c"])
iex> Explorer.Series.count(s)
2

With :nan (:nan does not count as nil):

iex> s = Explorer.Series.from_list([1, :nan, 3])
iex> Explorer.Series.count(s)
3
Link to this function

covariance(left, right, ddof \\ 1)

View Source
@spec covariance(
  left :: t() | number(),
  right :: t() | number(),
  ddof :: non_neg_integer()
) :: float() | non_finite() | nil

Compute the covariance between two series.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s1 = Series.from_list([1, 8, 3])
iex> s2 = Series.from_list([4, 5, 2])
iex> Series.covariance(s1, s2)
3.0
Link to this function

cut(series, bins, opts \\ [])

View Source

Bins values into discrete values.

Given a bins length of N, there will be N+1 categories.

Options

  • :labels - The labels assigned to the bins. Given bins of length N, :labels must be of length N+1. Defaults to the bin bounds (e.g. (-inf -1.0], (-1.0, 1.0], (1.0, inf])

  • :break_point_label - The name given to the breakpoint column. Defaults to break_point.

  • :category_label - The name given to the category column. Defaults to category.

Examples

iex> s = Explorer.Series.from_list([1.0, 2.0, 3.0])
iex> Explorer.Series.cut(s, [1.5, 2.5])
#Explorer.DataFrame<
  Polars[3 x 3]
  values f64 [1.0, 2.0, 3.0]
  break_point f64 [1.5, 2.5, Inf]
  category category ["(-inf, 1.5]", "(1.5, 2.5]", "(2.5, inf]"]
>

Creates a new dataframe with unique values and the frequencies of each.

Examples

iex> s = Explorer.Series.from_list(["a", "a", "b", "c", "c", "c"])
iex> Explorer.Series.frequencies(s)
#Explorer.DataFrame<
  Polars[3 x 2]
  values string ["c", "a", "b"]
  counts u32 [3, 2, 1]
>
@spec max(series :: t()) ::
  number() | non_finite() | Date.t() | Time.t() | NaiveDateTime.t() | nil

Gets the maximum value of the series.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :date
  • :time
  • :datetime
  • :duration

Examples

iex> s = Explorer.Series.from_list([1, 2, nil, 3])
iex> Explorer.Series.max(s)
3

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, 3.0])
iex> Explorer.Series.max(s)
3.0

iex> s = Explorer.Series.from_list([~D[2021-01-01], ~D[1999-12-31]])
iex> Explorer.Series.max(s)
~D[2021-01-01]

iex> s = Explorer.Series.from_list([~N[2021-01-01 00:00:00], ~N[1999-12-31 00:00:00]])
iex> Explorer.Series.max(s)
~N[2021-01-01 00:00:00.000000]

iex> s = Explorer.Series.from_list([~T[00:02:03.000212], ~T[00:05:04.000456]])
iex> Explorer.Series.max(s)
~T[00:05:04.000456]

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.max(s)
** (ArgumentError) Explorer.Series.max/1 not implemented for dtype :string. Valid dtypes are :date, :time, {:datetime, :microsecond}, {:datetime, :millisecond}, {:datetime, :nanosecond}, {:duration, :microsecond}, {:duration, :millisecond}, {:duration, :nanosecond}, {:f, 32}, {:f, 64}, {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
@spec mean(series :: t()) :: float() | non_finite() | nil

Gets the mean value of the series.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s = Explorer.Series.from_list([1, 2, nil, 3])
iex> Explorer.Series.mean(s)
2.0

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, 3.0])
iex> Explorer.Series.mean(s)
2.0

iex> s = Explorer.Series.from_list([~D[2021-01-01], ~D[1999-12-31]])
iex> Explorer.Series.mean(s)
** (ArgumentError) Explorer.Series.mean/1 not implemented for dtype :date. Valid dtypes are {:f, 32}, {:f, 64}, {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
@spec median(series :: t()) :: float() | non_finite() | nil

Gets the median value of the series.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s = Explorer.Series.from_list([1, 2, nil, 3])
iex> Explorer.Series.median(s)
2.0

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, 3.0])
iex> Explorer.Series.median(s)
2.0

iex> s = Explorer.Series.from_list([~D[2021-01-01], ~D[1999-12-31]])
iex> Explorer.Series.median(s)
** (ArgumentError) Explorer.Series.median/1 not implemented for dtype :date. Valid dtypes are {:f, 32}, {:f, 64}, {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
@spec min(series :: t()) ::
  number() | non_finite() | Date.t() | Time.t() | NaiveDateTime.t() | nil

Gets the minimum value of the series.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :date
  • :time
  • :datetime
  • :duration

Examples

iex> s = Explorer.Series.from_list([1, 2, nil, 3])
iex> Explorer.Series.min(s)
1

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, 3.0])
iex> Explorer.Series.min(s)
1.0

iex> s = Explorer.Series.from_list([~D[2021-01-01], ~D[1999-12-31]])
iex> Explorer.Series.min(s)
~D[1999-12-31]

iex> s = Explorer.Series.from_list([~N[2021-01-01 00:00:00], ~N[1999-12-31 00:00:00]])
iex> Explorer.Series.min(s)
~N[1999-12-31 00:00:00.000000]

iex> s = Explorer.Series.from_list([~T[00:02:03.000451], ~T[00:05:04.000134]])
iex> Explorer.Series.min(s)
~T[00:02:03.000451]

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.min(s)
** (ArgumentError) Explorer.Series.min/1 not implemented for dtype :string. Valid dtypes are :date, :time, {:datetime, :microsecond}, {:datetime, :millisecond}, {:datetime, :nanosecond}, {:duration, :microsecond}, {:duration, :millisecond}, {:duration, :nanosecond}, {:f, 32}, {:f, 64}, {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
@spec mode(series :: t()) :: t() | nil

Gets the most common value(s) of the series.

This function will return multiple values when there's a tie.

Supported dtypes

All except :list and :struct.

Examples

iex> s = Explorer.Series.from_list([1, 2, 2, nil])
iex> Explorer.Series.mode(s)
#Explorer.Series<
  Polars[1]
  s64 [2]
>

iex> s = Explorer.Series.from_list(["a", "b", "b", "c"])
iex> Explorer.Series.mode(s)
#Explorer.Series<
  Polars[1]
  string ["b"]
>

This function can return multiple entries, but the order is not guaranteed. You may sort the series if desired.

iex> s = Explorer.Series.from_list([1.0, 2.0, 2.0, 3.0, 3.0])
iex> Explorer.Series.mode(s) |> Explorer.Series.sort()
#Explorer.Series<
  Polars[2]
  f64 [2.0, 3.0]
>

Returns the number of unique values in the series.

Examples

iex> s = Explorer.Series.from_list(["a", "b", "a", "b"])
iex> Explorer.Series.n_distinct(s)
2

Counts the number of nil elements in a series.

When used in a query on grouped data, count_nil/1 is a per-group operation.

See also:

  • count/1 - counts only the non-nil elements.
  • size/1 - counts all elements.

Examples

Without nils:

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.nil_count(s)
0

With nils:

iex> s = Explorer.Series.from_list(["a", nil, "c"])
iex> Explorer.Series.nil_count(s)
1

With :nans (:nan does not count as nil):

iex> s = Explorer.Series.from_list([1, :nan, 3])
iex> Explorer.Series.nil_count(s)
0
@spec product(series :: t()) :: float() | non_finite() | nil

Reduce this Series to the product value.

Note that an empty series is going to result in a product of 1. Values that are nil are ignored.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.product(s)
6

iex> s = Explorer.Series.from_list([], dtype: :float)
iex> Explorer.Series.product(s)
1.0

iex> s = Explorer.Series.from_list([true, false, true])
iex> Explorer.Series.product(s)
** (ArgumentError) Explorer.Series.product/1 not implemented for dtype :boolean. Valid dtypes are {:f, 32}, {:f, 64}, {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
Link to this function

qcut(series, quantiles, opts \\ [])

View Source

Bins values into discrete values base on their quantiles.

Given a quantiles length of N, there will be N+1 categories. Each element of quantiles is expected to be between 0.0 and 1.0.

Options

  • :labels - The labels assigned to the bins. Given bins of length N, :labels must be of length N+1. Defaults to the bin bounds (e.g. (-inf -1.0], (-1.0, 1.0], (1.0, inf])

  • :break_point_label - The name given to the breakpoint column. Defaults to break_point.

  • :category_label - The name given to the category column. Defaults to category.

Examples

iex> s = Explorer.Series.from_list([1.0, 2.0, 3.0, 4.0, 5.0])
iex> Explorer.Series.qcut(s, [0.25, 0.75])
#Explorer.DataFrame<
  Polars[5 x 3]
  values f64 [1.0, 2.0, 3.0, 4.0, 5.0]
  break_point f64 [2.0, 2.0, 4.0, 4.0, Inf]
  category category ["(-inf, 2]", "(-inf, 2]", "(2, 4]", "(2, 4]", "(4, inf]"]
>
Link to this function

quantile(series, quantile)

View Source
@spec quantile(series :: t(), quantile :: float()) :: any()

Gets the given quantile of the series.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :date
  • :time
  • :datetime
  • :duration

Examples

iex> s = Explorer.Series.from_list([1, 2, nil, 3])
iex> Explorer.Series.quantile(s, 0.2)
1

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, 3.0])
iex> Explorer.Series.quantile(s, 0.5)
2.0

iex> s = Explorer.Series.from_list([~D[2021-01-01], ~D[1999-12-31]])
iex> Explorer.Series.quantile(s, 0.5)
~D[2021-01-01]

iex> s = Explorer.Series.from_list([~N[2021-01-01 00:00:00], ~N[1999-12-31 00:00:00]])
iex> Explorer.Series.quantile(s, 0.5)
~N[2021-01-01 00:00:00.000000]

iex> s = Explorer.Series.from_list([~T[01:55:00], ~T[15:35:00], ~T[23:00:00]])
iex> Explorer.Series.quantile(s, 0.5)
~T[15:35:00]

iex> s = Explorer.Series.from_list([true, false, true])
iex> Explorer.Series.quantile(s, 0.5)
** (ArgumentError) Explorer.Series.quantile/2 not implemented for dtype :boolean. Valid dtypes are :date, :time, {:datetime, :microsecond}, {:datetime, :millisecond}, {:datetime, :nanosecond}, {:duration, :microsecond}, {:duration, :millisecond}, {:duration, :nanosecond}, {:f, 32}, {:f, 64}, {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
Link to this function

skew(series, opts \\ [])

View Source
@spec skew(series :: t(), opts :: Keyword.t()) :: float() | non_finite() | nil

Compute the sample skewness of a series.

For normally distributed data, the skewness should be about zero.

For unimodal continuous distributions, a skewness value greater than zero means that there is more weight in the right tail of the distribution.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s = Explorer.Series.from_list([1, 2, 3, 4, 5, 23])
iex> Explorer.Series.skew(s)
1.6727687946848508

iex> s = Explorer.Series.from_list([1, 2, 3, 4, 5, 23])
iex> Explorer.Series.skew(s, bias: false)
2.2905330058490514

iex> s = Explorer.Series.from_list([1, 2, 3, nil, 1])
iex> Explorer.Series.skew(s, bias: false)
0.8545630383279712

iex> s = Explorer.Series.from_list([1, 2, 3, nil, 1])
iex> Explorer.Series.skew(s)
0.49338220021815865

iex> s = Explorer.Series.from_list([true, false, true])
iex> Explorer.Series.skew(s, false)
** (ArgumentError) Explorer.Series.skew/2 not implemented for dtype :boolean. Valid dtypes are {:f, 32}, {:f, 64}, {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
Link to this function

standard_deviation(series, ddof \\ 1)

View Source
@spec standard_deviation(series :: t(), ddof :: non_neg_integer()) ::
  float() | non_finite() | nil

Gets the standard deviation of the series.

By default, this is the sample standard deviation. This function also takes an optional delta degrees of freedom (ddof). Setting this to zero corresponds to the population sample standard deviation.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s = Explorer.Series.from_list([1, 2, nil, 3])
iex> Explorer.Series.standard_deviation(s)
1.0

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, 3.0])
iex> Explorer.Series.standard_deviation(s)
1.0

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.standard_deviation(s)
** (ArgumentError) Explorer.Series.standard_deviation/1 not implemented for dtype :string. Valid dtypes are {:f, 32}, {:f, 64}, {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
@spec sum(series :: t()) :: number() | non_finite() | nil

Gets the sum of the series.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :boolean

Examples

iex> s = Explorer.Series.from_list([1, 2, nil, 3])
iex> Explorer.Series.sum(s)
6

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, 3.0])
iex> Explorer.Series.sum(s)
6.0

iex> s = Explorer.Series.from_list([true, false, true])
iex> Explorer.Series.sum(s)
2

iex> s = Explorer.Series.from_list([~D[2021-01-01], ~D[1999-12-31]])
iex> Explorer.Series.sum(s)
** (ArgumentError) Explorer.Series.sum/1 not implemented for dtype :date. Valid dtypes are :boolean, {:f, 32}, {:f, 64}, {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
Link to this function

variance(series, ddof \\ 1)

View Source
@spec variance(series :: t(), ddof :: non_neg_integer()) ::
  float() | non_finite() | nil

Gets the variance of the series.

By default, this is the sample variance. This function also takes an optional delta degrees of freedom (ddof). Setting this to zero corresponds to the population variance.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s = Explorer.Series.from_list([1, 2, nil, 3])
iex> Explorer.Series.variance(s)
1.0

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, 3.0])
iex> Explorer.Series.variance(s)
1.0

iex> s = Explorer.Series.from_list([~N[2021-01-01 00:00:00], ~N[1999-12-31 00:00:00]])
iex> Explorer.Series.variance(s)
** (ArgumentError) Explorer.Series.variance/1 not implemented for dtype {:datetime, :microsecond}. Valid dtypes are {:f, 32}, {:f, 64}, {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Functions: Element-wise

@spec abs(series :: t()) :: t()

Gets the series absolute values.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s = Explorer.Series.from_list([1, 2, -1, -3])
iex> Explorer.Series.abs(s)
#Explorer.Series<
  Polars[4]
  s64 [1, 2, 1, 3]
>

iex> s = Explorer.Series.from_list([1.0, 2.0, -1.0, -3.0])
iex> Explorer.Series.abs(s)
#Explorer.Series<
  Polars[4]
  f64 [1.0, 2.0, 1.0, 3.0]
>

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, -3.0])
iex> Explorer.Series.abs(s)
#Explorer.Series<
  Polars[4]
  f64 [1.0, 2.0, nil, 3.0]
>

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.abs(s)
** (ArgumentError) Explorer.Series.abs/1 not implemented for dtype :string. Valid dtypes are {:f, 32}, {:f, 64}, {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
@spec add(
  left :: t() | number() | Date.t() | NaiveDateTime.t() | Explorer.Duration.t(),
  right :: t() | number() | Date.t() | NaiveDateTime.t() | Explorer.Duration.t()
) :: t()

Adds right to left, element-wise.

When mixing floats and integers, the resulting series will have dtype {:f, 64}.

At least one of the arguments must be a series. If both sizes are series, the series must have the same size or at last one of them must have size of 1.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> s2 = Explorer.Series.from_list([4, 5, 6])
iex> Explorer.Series.add(s1, s2)
#Explorer.Series<
  Polars[3]
  s64 [5, 7, 9]
>

You can also use scalar values on both sides:

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.add(s1, 2)
#Explorer.Series<
  Polars[3]
  s64 [3, 4, 5]
>

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.add(2, s1)
#Explorer.Series<
  Polars[3]
  s64 [3, 4, 5]
>

Checks equality between two entire series.

Examples

iex> s1 = Explorer.Series.from_list(["a", "b"])
iex> s2 = Explorer.Series.from_list(["a", "b"])
iex> Explorer.Series.all_equal(s1, s2)
true

iex> s1 = Explorer.Series.from_list(["a", "b"])
iex> s2 = Explorer.Series.from_list(["a", "c"])
iex> Explorer.Series.all_equal(s1, s2)
false

iex> s1 = Explorer.Series.from_list(["a", "b"])
iex> s2 = Explorer.Series.from_list([1, 2])
iex> Explorer.Series.all_equal(s1, s2)
false

Returns a boolean mask of left and right, element-wise.

Both sizes must be series, the series must have the same size or at last one of them must have size of 1.

Examples

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> mask1 = Explorer.Series.greater(s1, 1)
iex> mask2 = Explorer.Series.less(s1, 3)
iex> Explorer.Series.and(mask1, mask2)
#Explorer.Series<
  Polars[3]
  boolean [false, true, false]
>
@spec cast(series :: t(), dtype :: dtype()) :: t()

Cast the series to another type.

Examples

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.cast(s, :string)
#Explorer.Series<
  Polars[3]
  string ["1", "2", "3"]
>

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.cast(s, {:f, 64})
#Explorer.Series<
  Polars[3]
  f64 [1.0, 2.0, 3.0]
>

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.cast(s, :date)
#Explorer.Series<
  Polars[3]
  date [1970-01-02, 1970-01-03, 1970-01-04]
>

Note that time is represented as an integer of nanoseconds since midnight. In Elixir we can't represent nanoseconds, only microseconds. So be aware that information can be lost if a conversion is needed (e.g. calling to_list/1).

iex> s = Explorer.Series.from_list([1_000, 2_000, 3_000])
iex> Explorer.Series.cast(s, :time)
#Explorer.Series<
  Polars[3]
  time [00:00:00.000001, 00:00:00.000002, 00:00:00.000003]
>

iex> s = Explorer.Series.from_list([86399 * 1_000 * 1_000 * 1_000])
iex> Explorer.Series.cast(s, :time)
#Explorer.Series<
  Polars[1]
  time [23:59:59.000000]
>

Note that datetime is represented as an integer of microseconds since Unix Epoch (1970-01-01 00:00:00).

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.cast(s, {:datetime, :microsecond})
#Explorer.Series<
  Polars[3]
  datetime[μs] [1970-01-01 00:00:00.000001, 1970-01-01 00:00:00.000002, 1970-01-01 00:00:00.000003]
>

iex> s = Explorer.Series.from_list([1649883642 * 1_000 * 1_000])
iex> Explorer.Series.cast(s, {:datetime, :microsecond})
#Explorer.Series<
  Polars[1]
  datetime[μs] [2022-04-13 21:00:42.000000]
>

You can also use cast/2 to categorise a string:

iex> s = Explorer.Series.from_list(["apple", "banana",  "apple", "lemon"])
iex> Explorer.Series.cast(s, :category)
#Explorer.Series<
  Polars[4]
  category ["apple", "banana", "apple", "lemon"]
>

cast/2 will return the series as a no-op if you try to cast to the same dtype.

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.cast(s, :integer)
#Explorer.Series<
  Polars[3]
  s64 [1, 2, 3]
>
Link to this function

categorise(series, categories)

View Source

Categorise a series of integers or strings according to categories.

This function receives a series of integers or strings and convert them into the categories specified by the second argument. The second argument can be one of:

  • a series with dtype :category. The integers will be indexes into the categories of the given series (returned by categories/1)

  • a series with dtype :string. The integers will be indexes into the series itself

  • a list of strings. The integers will be indexes into the list

This is going to essentially "copy" the source of categories from the left series to the right. All members from the left that are not present in the right hand-side are going to be nil.

If you have a series of strings and you want to convert them into categories, invoke cast(series, :category) instead.

Examples

If a categorical series is given as second argument, we will extract its categories and map the integers into it:

iex> categories = Explorer.Series.from_list(["a", "b", "c", nil, "a"], dtype: :category)
iex> indexes = Explorer.Series.from_list([0, 2, 1, 0, 2])
iex> Explorer.Series.categorise(indexes, categories)
#Explorer.Series<
  Polars[5]
  category ["a", "c", "b", "a", "c"]
>

Otherwise, if a list of strings or a series of strings is given, they are considered to be the categories series itself:

iex> categories = Explorer.Series.from_list(["a", "b", "c"])
iex> indexes = Explorer.Series.from_list([0, 2, 1, 0, 2])
iex> Explorer.Series.categorise(indexes, categories)
#Explorer.Series<
  Polars[5]
  category ["a", "c", "b", "a", "c"]
>

iex> indexes = Explorer.Series.from_list([0, 2, 1, 0, 2])
iex> Explorer.Series.categorise(indexes, ["a", "b", "c"])
#Explorer.Series<
  Polars[5]
  category ["a", "c", "b", "a", "c"]
>

Elements that are not mapped to a category will become nil:

iex> indexes = Explorer.Series.from_list([0, 2, nil, 0, 2, 7])
iex> Explorer.Series.categorise(indexes, ["a", "b", "c"])
#Explorer.Series<
  Polars[6]
  category ["a", "c", nil, "a", "c", nil]
>

Strings can be used as "indexes" to create a categorical series with the intersection of members:

iex> strings = Explorer.Series.from_list(["a", "c", nil, "c", "b", "d"])
iex> Explorer.Series.categorise(strings, ["a", "b", "c"])
#Explorer.Series<
  Polars[6]
  category ["a", "c", nil, "c", "b", nil]
>
@spec clip(series :: t(), min :: number(), max :: number()) :: t()

Clip (or clamp) the values in a series.

Values that fall outside of the interval defined by the min and max bounds are clipped to the bounds.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Clipping other dtypes are possible using select/3.

Examples

iex> s = Explorer.Series.from_list([-50, 5, nil, 50])
iex> Explorer.Series.clip(s, 1, 10)
#Explorer.Series<
  Polars[4]
  s64 [1, 5, nil, 10]
>

iex> s = Explorer.Series.from_list([-50, 5, nil, 50])
iex> Explorer.Series.clip(s, 1.5, 10.5)
#Explorer.Series<
  Polars[4]
  f64 [1.5, 5.0, nil, 10.5]
>
@spec coalesce([t()]) :: t()

Finds the first non-missing element at each position.

Examples

iex> s1 = Explorer.Series.from_list([1, 2, nil, nil])
iex> s2 = Explorer.Series.from_list([1, 2, nil, 4])
iex> s3 = Explorer.Series.from_list([nil, nil, 3, 4])
iex> Explorer.Series.coalesce([s1, s2, s3])
#Explorer.Series<
  Polars[4]
  s64 [1, 2, 3, 4]
>
@spec coalesce(s1 :: t(), s2 :: t()) :: t()

Finds the first non-missing element at each position.

coalesce(s1, s2) is equivalent to coalesce([s1, s2]).

Examples

iex> s1 = Explorer.Series.from_list([1, nil, 3, nil])
iex> s2 = Explorer.Series.from_list([1, 2, nil, 4])
iex> Explorer.Series.coalesce(s1, s2)
#Explorer.Series<
  Polars[4]
  s64 [1, 2, 3, 4]
>

iex> s1 = Explorer.Series.from_list(["foo", nil, "bar", nil])
iex> s2 = Explorer.Series.from_list([1, 2, nil, 4])
iex> Explorer.Series.coalesce(s1, s2)
** (ArgumentError) cannot invoke Explorer.Series.coalesce/2 with mismatched dtypes: :string and {:s, 64}
@spec divide(
  left :: t() | number() | Explorer.Duration.t(),
  right :: t() | number()
) :: t()

Divides left by right, element-wise.

The resulting series will have the dtype as {:f, 64}.

At least one of the arguments must be a series. If both sizes are series, the series must have the same size or at last one of them must have size of 1.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s1 = [10, 10, 10] |> Explorer.Series.from_list()
iex> s2 = [2, 2, 2] |> Explorer.Series.from_list()
iex> Explorer.Series.divide(s1, s2)
#Explorer.Series<
  Polars[3]
  f64 [5.0, 5.0, 5.0]
>

iex> s1 = [10, 10, 10] |> Explorer.Series.from_list()
iex> Explorer.Series.divide(s1, 2)
#Explorer.Series<
  Polars[3]
  f64 [5.0, 5.0, 5.0]
>

iex> s1 = [10, 52 ,10] |> Explorer.Series.from_list()
iex> Explorer.Series.divide(s1, 2.5)
#Explorer.Series<
  Polars[3]
  f64 [4.0, 20.8, 4.0]
>

iex> s1 = [10, 10, 10] |> Explorer.Series.from_list()
iex> s2 = [2, 0, 2] |> Explorer.Series.from_list()
iex> Explorer.Series.divide(s1, s2)
#Explorer.Series<
  Polars[3]
  f64 [5.0, Inf, 5.0]
>
@spec equal(
  left ::
    t() | number() | Date.t() | NaiveDateTime.t() | boolean() | String.t(),
  right ::
    t() | number() | Date.t() | NaiveDateTime.t() | boolean() | String.t()
) :: t()

Returns boolean mask of left == right, element-wise.

At least one of the arguments must be a series. If both sizes are series, the series must have the same size or at last one of them must have size of 1.

Examples

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> s2 = Explorer.Series.from_list([1, 2, 4])
iex> Explorer.Series.equal(s1, s2)
#Explorer.Series<
  Polars[3]
  boolean [true, true, false]
>

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.equal(s, 1)
#Explorer.Series<
  Polars[3]
  boolean [true, false, false]
>

iex> s = Explorer.Series.from_list([true, true, false])
iex> Explorer.Series.equal(s, true)
#Explorer.Series<
  Polars[3]
  boolean [true, true, false]
>

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.equal(s, "a")
#Explorer.Series<
  Polars[3]
  boolean [true, false, false]
>

iex> s = Explorer.Series.from_list([~D[2021-01-01], ~D[1999-12-31]])
iex> Explorer.Series.equal(s, ~D[1999-12-31])
#Explorer.Series<
  Polars[2]
  boolean [false, true]
>

iex> s = Explorer.Series.from_list([~N[2022-01-01 00:00:00], ~N[2022-01-01 23:00:00]])
iex> Explorer.Series.equal(s, ~N[2022-01-01 00:00:00])
#Explorer.Series<
  Polars[2]
  boolean [true, false]
>

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.equal(s, false)
** (ArgumentError) cannot invoke Explorer.Series.equal/2 with mismatched dtypes: :string and false
@spec exp(t()) :: t()

Calculates the exponential of all elements.

Link to this macro

filter(series, query)

View Source (macro)

Picks values based on an Explorer.Query.

The query is compiled and runs efficiently against the series. The query must return a boolean expression or a list of boolean expressions. When a list is returned, they are joined as and expressions.

Notice

This is a macro.

  • You must require Explorer.Series before using it.
  • You must use the special _ syntax. See the moduledoc for details.

Besides element-wise series operations, you can also use window functions and aggregations inside comparisons.

See filter_with/2 for a callback version of this function without Explorer.Query. See mask/2 if you want to filter values based on another series.

Examples

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.filter(s, _ == "b")
#Explorer.Series<
  Polars[1]
  string ["b"]
>

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.filter(s, remainder(_, 2) == 1)
#Explorer.Series<
  Polars[2]
  s64 [1, 3]
>

Returning a non-boolean expression errors:

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.filter(s, cumulative_max(_))
** (ArgumentError) expecting the function to return a boolean LazySeries, but instead it returned a LazySeries of type {:s, 64}

Which can be addressed by converting it to boolean:

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.filter(s, cumulative_max(_) == 1)
#Explorer.Series<
  Polars[1]
  s64 [1]
>
Link to this function

filter_with(series, fun)

View Source
@spec filter_with(
  series :: t(),
  fun :: (t() -> lazy_t())
) :: t()

Filters a series with a callback function.

See mask/2 if you want to filter values based on another series.

Examples

iex> series = Explorer.Series.from_list([1, 2, 3])
iex> is_odd = fn s -> s |> Explorer.Series.remainder(2) |> Explorer.Series.equal(1) end
iex> Explorer.Series.filter_with(series, is_odd)
#Explorer.Series<
  Polars[2]
  s64 [1, 3]
>
@spec greater(
  left :: t() | number() | Date.t() | NaiveDateTime.t(),
  right :: t() | number() | Date.t() | NaiveDateTime.t()
) :: t()

Returns boolean mask of left > right, element-wise.

At least one of the arguments must be a series. If both sizes are series, the series must have the same size or at last one of them must have size of 1.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :date
  • :time
  • :datetime
  • :duration

Examples

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> s2 = Explorer.Series.from_list([1, 2, 4])
iex> Explorer.Series.greater(s1, s2)
#Explorer.Series<
  Polars[3]
  boolean [false, false, false]
>
Link to this function

greater_equal(left, right)

View Source
@spec greater_equal(
  left :: t() | number() | Date.t() | NaiveDateTime.t(),
  right :: t() | number() | Date.t() | NaiveDateTime.t()
) :: t()

Returns boolean mask of left >= right, element-wise.

At least one of the arguments must be a series. If both sizes are series, the series must have the same size or at last one of them must have size of 1.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :date
  • :time
  • :datetime
  • :duration

Examples

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> s2 = Explorer.Series.from_list([1, 2, 4])
iex> Explorer.Series.greater_equal(s1, s2)
#Explorer.Series<
  Polars[3]
  boolean [true, true, false]
>

Checks if each element of the series in the left exists in the series on the right, returning a boolean mask.

The series sizes do not have to match.

See member?/2 if you want to check if a literal belongs to a list.

Examples

iex> left = Explorer.Series.from_list([1, 2, 3])
iex> right = Explorer.Series.from_list([1, 2])
iex> Series.in(left, right)
#Explorer.Series<
  Polars[3]
  boolean [true, true, false]
>

iex> left = Explorer.Series.from_list([~D[1970-01-01], ~D[2000-01-01], ~D[2010-04-17]])
iex> right = Explorer.Series.from_list([~D[1970-01-01], ~D[2010-04-17]])
iex> Series.in(left, right)
#Explorer.Series<
  Polars[3]
  boolean [true, false, true]
>
@spec is_nil(t()) :: t()

Returns a mask of nil values.

Examples

iex> s = Explorer.Series.from_list([1, 2, nil, 4])
iex> Explorer.Series.is_nil(s)
#Explorer.Series<
  Polars[4]
  boolean [false, false, true, false]
>
@spec is_not_nil(t()) :: t()

Returns a mask of not nil values.

Examples

iex> s = Explorer.Series.from_list([1, 2, nil, 4])
iex> Explorer.Series.is_not_nil(s)
#Explorer.Series<
  Polars[4]
  boolean [true, true, false, true]
>
@spec less(
  left :: t() | number() | Date.t() | NaiveDateTime.t(),
  right :: t() | number() | Date.t() | NaiveDateTime.t()
) :: t()

Returns boolean mask of left < right, element-wise.

At least one of the arguments must be a series. If both sizes are series, the series must have the same size or at last one of them must have size of 1.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :date
  • :time
  • :datetime
  • :duration

Examples

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> s2 = Explorer.Series.from_list([1, 2, 4])
iex> Explorer.Series.less(s1, s2)
#Explorer.Series<
  Polars[3]
  boolean [false, false, true]
>
@spec less_equal(
  left :: t() | number() | Date.t() | NaiveDateTime.t(),
  right :: t() | number() | Date.t() | NaiveDateTime.t()
) :: t()

Returns boolean mask of left <= right, element-wise.

At least one of the arguments must be a series. If both sizes are series, the series must have the same size or at last one of them must have size of 1.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :date
  • :time
  • :datetime
  • :duration

Examples

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> s2 = Explorer.Series.from_list([1, 2, 4])
iex> Explorer.Series.less_equal(s1, s2)
#Explorer.Series<
  Polars[3]
  boolean [true, true, true]
>
@spec log(argument :: t()) :: t()

Calculates the natural logarithm.

The resultant series is going to be of dtype {:f, 64}. See log/2 for passing a custom base.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s = Explorer.Series.from_list([1, 2, 3, nil, 4])
iex> Explorer.Series.log(s)
#Explorer.Series<
  Polars[5]
  f64 [0.0, 0.6931471805599453, 1.0986122886681098, nil, 1.3862943611198906]
>
@spec log(argument :: t(), base :: number()) :: t()

Calculates the logarithm on a given base.

The resultant series is going to be of dtype {:f, 64}.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s = Explorer.Series.from_list([8, 16, 32])
iex> Explorer.Series.log(s, 2)
#Explorer.Series<
  Polars[3]
  f64 [3.0, 4.0, 5.0]
>
Link to this macro

map(series, query)

View Source (macro)

Maps values based on an Explorer.Query.

The query is compiled and runs efficiently against the series.

Notice

This is a macro.

  • You must require Explorer.Series before using it.
  • You must use the special _ syntax. See the moduledoc for details.

See map_with/2 for a callback version of this function without Explorer.Query.

This function only works with lazy computations. See transform/2 for a version that works with any Elixir function.

Examples

Basic example:

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.map(s, _ * 2)
#Explorer.Series<
  Polars[3]
  s64 [2, 4, 6]
>

You can also use window functions and aggregations:

iex> s = Explorer.Series.from_list([2, 3, 4])
iex> Explorer.Series.map(s, _ - min(_))
#Explorer.Series<
  Polars[3]
  s64 [0, 1, 2]
>

Maps a series with a callback function.

This function only works with lazy computations. See transform/2 for a version that works with any Elixir function.

Examples

iex> series = Explorer.Series.from_list([2, 3, 4])
iex> shift_left = fn s -> Explorer.Series.subtract(s, Explorer.Series.min(s)) end
iex> Explorer.Series.map_with(series, shift_left)
#Explorer.Series<
  Polars[3]
  s64 [0, 1, 2]
>
@spec mask(series :: t(), mask :: t()) :: t()

Filters a series with a mask.

Examples

iex> s1 = Explorer.Series.from_list([1,2,3])
iex> s2 = Explorer.Series.from_list([true, false, true])
iex> Explorer.Series.mask(s1, s2)
#Explorer.Series<
  Polars[2]
  s64 [1, 3]
>
@spec multiply(
  left :: t() | number() | Explorer.Duration.t(),
  right :: t() | number() | Explorer.Duration.t()
) :: t()

Multiplies left and right, element-wise.

When mixing floats and integers, the resulting series will have dtype {:f, 64}.

At least one of the arguments must be a series. If both sizes are series, the series must have the same size or at last one of them must have size of 1.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s1 = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> s2 = 11..20 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.multiply(s1, s2)
#Explorer.Series<
  Polars[10]
  s64 [11, 24, 39, 56, 75, 96, 119, 144, 171, 200]
>

iex> s1 = 1..5 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.multiply(s1, 2)
#Explorer.Series<
  Polars[5]
  s64 [2, 4, 6, 8, 10]
>

Negate the elements of a boolean series.

Examples

iex> s1 = Explorer.Series.from_list([true, false, false])
iex> Explorer.Series.not(s1)
#Explorer.Series<
  Polars[3]
  boolean [false, true, true]
>
@spec not_equal(
  left ::
    t() | number() | Date.t() | NaiveDateTime.t() | boolean() | String.t(),
  right ::
    t() | number() | Date.t() | NaiveDateTime.t() | boolean() | String.t()
) :: t()

Returns boolean mask of left != right, element-wise.

At least one of the arguments must be a series. If both sizes are series, the series must have the same size or at last one of them must have size of 1.

Examples

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> s2 = Explorer.Series.from_list([1, 2, 4])
iex> Explorer.Series.not_equal(s1, s2)
#Explorer.Series<
  Polars[3]
  boolean [false, false, true]
>

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.not_equal(s, 1)
#Explorer.Series<
  Polars[3]
  boolean [false, true, true]
>

iex> s = Explorer.Series.from_list([true, true, false])
iex> Explorer.Series.not_equal(s, true)
#Explorer.Series<
  Polars[3]
  boolean [false, false, true]
>

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.not_equal(s, "a")
#Explorer.Series<
  Polars[3]
  boolean [false, true, true]
>

iex> s = Explorer.Series.from_list([~D[2021-01-01], ~D[1999-12-31]])
iex> Explorer.Series.not_equal(s, ~D[1999-12-31])
#Explorer.Series<
  Polars[2]
  boolean [true, false]
>

iex> s = Explorer.Series.from_list([~N[2022-01-01 00:00:00], ~N[2022-01-01 23:00:00]])
iex> Explorer.Series.not_equal(s, ~N[2022-01-01 00:00:00])
#Explorer.Series<
  Polars[2]
  boolean [false, true]
>

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.not_equal(s, false)
** (ArgumentError) cannot invoke Explorer.Series.not_equal/2 with mismatched dtypes: :string and false

Returns a boolean mask of left or right, element-wise.

Both sizes must be series, the series must have the same size or at last one of them must have size of 1.

Examples

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> mask1 = Explorer.Series.less(s1, 2)
iex> mask2 = Explorer.Series.greater(s1, 2)
iex> Explorer.Series.or(mask1, mask2)
#Explorer.Series<
  Polars[3]
  boolean [true, false, true]
>
Link to this function

peaks(series, max_or_min \\ :max)

View Source
@spec peaks(series :: t(), max_or_min :: :max | :min) :: t()

Returns a boolean mask with true where the 'peaks' (series max or min, default max) are.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :date
  • :time
  • :datetime
  • :duration

Examples

iex> s = Explorer.Series.from_list([1, 2, 4, 1, 4])
iex> Explorer.Series.peaks(s)
#Explorer.Series<
  Polars[5]
  boolean [false, false, true, false, true]
>

iex> s = [~T[03:00:02.000000], ~T[13:24:56.000000], ~T[02:04:19.000000]] |> Explorer.Series.from_list()
iex> Explorer.Series.peaks(s)
#Explorer.Series<
  Polars[3]
  boolean [false, true, false]
>
@spec pow(left :: t() | number(), right :: t() | number()) :: t()

Raises a numeric series to the power of the exponent.

At least one of the arguments must be a series. If both sizes are series, the series must have the same size or at last one of them must have size of 1.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s = [8, 16, 32] |> Explorer.Series.from_list()
iex> Explorer.Series.pow(s, 2.0)
#Explorer.Series<
  Polars[3]
  f64 [64.0, 256.0, 1024.0]
>

iex> s = [2, 4, 6] |> Explorer.Series.from_list()
iex> Explorer.Series.pow(s, 3)
#Explorer.Series<
  Polars[3]
  f64 [8.0, 64.0, 216.0]
>

iex> s = [2, 4, 6] |> Explorer.Series.from_list()
iex> Explorer.Series.pow(s, -3.0)
#Explorer.Series<
  Polars[3]
  f64 [0.125, 0.015625, 0.004629629629629629]
>

iex> s = [1.0, 2.0, 3.0] |> Explorer.Series.from_list()
iex> Explorer.Series.pow(s, 3.0)
#Explorer.Series<
  Polars[3]
  f64 [1.0, 8.0, 27.0]
>

iex> s = [2.0, 4.0, 6.0] |> Explorer.Series.from_list()
iex> Explorer.Series.pow(s, 2)
#Explorer.Series<
  Polars[3]
  f64 [4.0, 16.0, 36.0]
>
@spec quotient(left :: t(), right :: t() | integer()) :: t()

Element-wise integer division.

At least one of the arguments must be a series. If both sizes are series, the series must have the same size or at last one of them must have size of 1.

Supported dtype

  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Returns nil if there is a zero in the right-hand side.

Examples

iex> s1 = [10, 11, 10] |> Explorer.Series.from_list()
iex> s2 = [2, 2, 2] |> Explorer.Series.from_list()
iex> Explorer.Series.quotient(s1, s2)
#Explorer.Series<
  Polars[3]
  s64 [5, 5, 5]
>

iex> s1 = [10, 11, 10] |> Explorer.Series.from_list()
iex> s2 = [2, 2, 0] |> Explorer.Series.from_list()
iex> Explorer.Series.quotient(s1, s2)
#Explorer.Series<
  Polars[3]
  s64 [5, 5, nil]
>

iex> s1 = [10, 12, 15] |> Explorer.Series.from_list()
iex> Explorer.Series.quotient(s1, 3)
#Explorer.Series<
  Polars[3]
  s64 [3, 4, 5]
>
Link to this function

rank(series, opts \\ [])

View Source
@spec rank(series :: t(), opts :: Keyword.t()) :: t()

Assign ranks to data with appropriate handling of tied values.

Options

  • :method - Determine how ranks are assigned to tied elements. The following methods are available:
    • :average : Each value receives the average rank that would be assigned to all tied values. (default)
    • :min : Tied values are assigned the minimum rank. Also known as "competition" ranking.
    • :max : Tied values are assigned the maximum of their ranks.
    • :dense : Similar to :min, but the rank of the next highest element is assigned the rank immediately after those assigned to the tied elements.
    • :ordinal : Each value is given a distinct rank based on its occurrence in the series.
    • :random : Similar to :ordinal, but the rank for ties is not dependent on the order that the values occur in the Series.
  • :descending - Rank in descending order.
  • :seed - An integer to be used as a random seed. If nil, a random value between 0 and 2^64 − 1 will be used. (default: nil)

Examples

iex> s = Explorer.Series.from_list([3, 6, 1, 1, 6])
iex> Explorer.Series.rank(s)
#Explorer.Series<
  Polars[5]
  f64 [3.0, 4.5, 1.5, 1.5, 4.5]
>

iex> s = Explorer.Series.from_list([1.1, 2.4, 3.2])
iex> Explorer.Series.rank(s, method: :ordinal)
#Explorer.Series<
  Polars[3]
  u32 [1, 2, 3]
>

iex> s = Explorer.Series.from_list([ ~N[2022-07-07 17:44:13.020548], ~N[2022-07-07 17:43:08.473561], ~N[2022-07-07 17:45:00.116337] ])
iex> Explorer.Series.rank(s, method: :average)
#Explorer.Series<
  Polars[3]
  f64 [2.0, 1.0, 3.0]
>

iex> s = Explorer.Series.from_list([3, 6, 1, 1, 6])
iex> Explorer.Series.rank(s, method: :min)
#Explorer.Series<
  Polars[5]
  s64 [3, 4, 1, 1, 4]
>

iex> s = Explorer.Series.from_list([3, 6, 1, 1, 6])
iex> Explorer.Series.rank(s, method: :dense)
#Explorer.Series<
  Polars[5]
  s64 [2, 3, 1, 1, 3]
>


iex> s = Explorer.Series.from_list([3, 6, 1, 1, 6])
iex> Explorer.Series.rank(s, method: :random, seed: 42)
#Explorer.Series<
  Polars[5]
  s64 [3, 4, 2, 1, 5]
>
@spec remainder(left :: t(), right :: t() | integer()) :: t()

Computes the remainder of an element-wise integer division.

At least one of the arguments must be a series. If both sizes are series, the series must have the same size or at last one of them must have size of 1.

Supported dtype

  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Returns nil if there is a zero in the right-hand side.

Examples

iex> s1 = [10, 11, 10] |> Explorer.Series.from_list()
iex> s2 = [2, 2, 2] |> Explorer.Series.from_list()
iex> Explorer.Series.remainder(s1, s2)
#Explorer.Series<
  Polars[3]
  s64 [0, 1, 0]
>

iex> s1 = [10, 11, 10] |> Explorer.Series.from_list()
iex> s2 = [2, 2, 0] |> Explorer.Series.from_list()
iex> Explorer.Series.remainder(s1, s2)
#Explorer.Series<
  Polars[3]
  s64 [0, 1, nil]
>

iex> s1 = [10, 11, 9] |> Explorer.Series.from_list()
iex> Explorer.Series.remainder(s1, 3)
#Explorer.Series<
  Polars[3]
  s64 [1, 2, 0]
>
@spec row_index(t()) :: t()

Returns a series of indexes for each item (row) in the series, starting from 0.

Examples

iex> s = Series.from_list([nil, true, true])
iex> Series.row_index(s)
#Explorer.Series<
  Polars[3]
  u32 [0, 1, 2]
>

This function can be used to add a row index as the first column of a dataframe. The resulting column is a regular column of type :u32.

iex> require Explorer.DataFrame, as: DF
iex> df = DF.new(a: [1, 3, 5], b: [2, 4, 6])
iex> DF.mutate(df, index: row_index(a)) |> DF.relocate("index", before: 0)
#Explorer.DataFrame<
  Polars[3 x 3]
  index u32 [0, 1, 2]
  a s64 [1, 3, 5]
  b s64 [2, 4, 6]
>
iex> df = DF.new(a: [1, 3, 5], b: [2, 4, 6])
iex> DF.mutate(df, id: row_index(a) + 1000)
#Explorer.DataFrame<
  Polars[3 x 3]
  a s64 [1, 3, 5]
  b s64 [2, 4, 6]
  id s64 [1000, 1001, 1002]
>
Link to this function

select(predicate, on_true, on_false)

View Source
@spec select(
  predicate :: t(),
  on_true :: t() | inferable_scalar(),
  on_false :: t() | inferable_scalar()
) :: t()

Returns a series from two series, based on a predicate.

The resulting series is built by evaluating each element of predicate and returning either the corresponding element from on_true or on_false.

predicate must be a boolean series. on_true and on_false must be a series of the same size as predicate or a series of size 1.

It is possible to mix numeric series in the on_true and on_false, and the resultant series will have the dtype of the greater side. For example, :u8 and :s16 is going to result in :s16 series.

Link to this function

strftime(series, format_string)

View Source
@spec strftime(series :: t(), format_string :: String.t()) :: t()

Converts a datetime series to a string series.

For the format string specification, refer to the chrono crate documentation.

Use cast(series, :string) for the default "%Y-%m-%d %H:%M:%S%.6f" format.

Examples

iex> s = Explorer.Series.from_list([~N[2023-01-05 12:34:56], nil])
iex> Explorer.Series.strftime(s, "%Y/%m/%d %H:%M:%S")
#Explorer.Series<
  Polars[2]
  string ["2023/01/05 12:34:56", nil]
>
Link to this function

strptime(series, format_string)

View Source
@spec strptime(series :: t(), format_string :: String.t()) :: t()

Converts a string series to a datetime series with a given format_string.

For the format string specification, refer to the chrono crate documentation.

Use cast(series, :datetime) if you prefer the format to be inferred (if possible).

Examples

iex> s = Explorer.Series.from_list(["2023-01-05 12:34:56", "XYZ", nil])
iex> Explorer.Series.strptime(s, "%Y-%m-%d %H:%M:%S")
#Explorer.Series<
  Polars[3]
  datetime[μs] [2023-01-05 12:34:56.000000, nil, nil]
>
@spec subtract(
  left :: t() | number() | Date.t() | NaiveDateTime.t() | Explorer.Duration.t(),
  right :: t() | number() | Date.t() | NaiveDateTime.t() | Explorer.Duration.t()
) :: t()

Subtracts right from left, element-wise.

When mixing floats and integers, the resulting series will have dtype {:f, 64}. In case both series are of unsigned integers, we will try to subtract, but an exception is raised if overflow occurs.

At least one of the arguments must be a series. If both sizes are series, the series must have the same size or at last one of them must have size of 1.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> s2 = Explorer.Series.from_list([4, 5, 6])
iex> Explorer.Series.subtract(s1, s2)
#Explorer.Series<
  Polars[3]
  s64 [-3, -3, -3]
>

You can also use scalar values on both sides:

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.subtract(s1, 2)
#Explorer.Series<
  Polars[3]
  s64 [-1, 0, 1]
>

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.subtract(2, s1)
#Explorer.Series<
  Polars[3]
  s64 [1, 0, -1]
>

Returns an Explorer.Series where each element is the result of invoking fun on each corresponding element of series.

This is an expensive operation meant to enable the use of arbitrary Elixir functions against any backend. The implementation will vary by backend but in most (all?) cases will require converting to an Elixir.List, applying Enum.map/2, and then converting back to an Explorer.Series.

Examples

iex> s = Explorer.Series.from_list(["this ", " is", "great   "])
iex> Explorer.Series.transform(s, &String.trim/1)
#Explorer.Series<
  Polars[3]
  string ["this", "is", "great"]
>

iex> s = Explorer.Series.from_list(["this", "is", "great"])
iex> Explorer.Series.transform(s, &String.length/1)
#Explorer.Series<
  Polars[3]
  s64 [4, 2, 5]
>

Functions: Datetime ops

@spec day_of_week(t()) :: t()

Returns a day-of-week number starting from Monday = 1. (ISO 8601 weekday number)

Examples

iex> s = Explorer.Series.from_list([~D[2023-01-15], ~D[2023-01-16], ~D[2023-01-20], nil])
iex> Explorer.Series.day_of_week(s)
#Explorer.Series<
  Polars[4]
  s8 [7, 1, 5, nil]
>

It can also be called on a datetime series.

iex> s = Explorer.Series.from_list([~N[2023-01-15 00:00:00], ~N[2023-01-16 23:59:59.999999], ~N[2023-01-20 12:00:00], nil])
iex> Explorer.Series.day_of_week(s)
#Explorer.Series<
  Polars[4]
  s8 [7, 1, 5, nil]
>
@spec day_of_year(t()) :: t()

Returns the day-of-year number starting from 1.

The return value ranges from 1 to 366 (the last day of year differs by years).

Examples

iex> s = Explorer.Series.from_list([~D[2023-01-01], ~D[2023-01-02], ~D[2023-02-01], nil])
iex> Explorer.Series.day_of_year(s)
#Explorer.Series<
  Polars[4]
  s16 [1, 2, 32, nil]
>

It can also be called on a datetime series.

iex> s = Explorer.Series.from_list(
...>   [~N[2023-01-01 00:00:00], ~N[2023-01-02 00:00:00], ~N[2023-02-01 23:59:59], nil]
...> )
iex> Explorer.Series.day_of_year(s)
#Explorer.Series<
  Polars[4]
  s16 [1, 2, 32, nil]
>
@spec hour(t()) :: t()

Returns the hour number from 0 to 23.

Examples

iex> s = Explorer.Series.from_list([~N[2023-01-15 00:00:00], ~N[2022-02-16 23:59:59.999999], ~N[2021-03-20 12:00:00], nil])
iex> Explorer.Series.hour(s)
#Explorer.Series<
  Polars[4]
  s8 [0, 23, 12, nil]
>
@spec minute(t()) :: t()

Returns the minute number from 0 to 59.

Examples

iex> s = Explorer.Series.from_list([~N[2023-01-15 00:00:00], ~N[2022-02-16 23:59:59.999999], ~N[2021-03-20 12:00:00], nil])
iex> Explorer.Series.minute(s)
#Explorer.Series<
  Polars[4]
  s8 [0, 59, 0, nil]
>
@spec month(t()) :: t()

Returns the month number starting from 1. The return value ranges from 1 to 12.

Examples

iex> s = Explorer.Series.from_list([~D[2023-01-15], ~D[2023-02-16], ~D[2023-03-20], nil])
iex> Explorer.Series.month(s)
#Explorer.Series<
  Polars[4]
  s8 [1, 2, 3, nil]
>

It can also be called on a datetime series.

iex> s = Explorer.Series.from_list([~N[2023-01-15 00:00:00], ~N[2023-02-16 23:59:59.999999], ~N[2023-03-20 12:00:00], nil])
iex> Explorer.Series.month(s)
#Explorer.Series<
  Polars[4]
  s8 [1, 2, 3, nil]
>
@spec second(t()) :: t()

Returns the second number from 0 to 59.

Examples

iex> s = Explorer.Series.from_list([~N[2023-01-15 00:00:00], ~N[2022-02-16 23:59:59.999999], ~N[2021-03-20 12:00:00], nil])
iex> Explorer.Series.second(s)
#Explorer.Series<
  Polars[4]
  s8 [0, 59, 0, nil]
>
@spec week_of_year(t()) :: t()

Returns the week-of-year number.

The return value ranges from 1 to 53 (the last week of year differs by years).

Weeks start on Monday and end on Sunday. If the final week of a year does not end on Sunday, the first days of the following year will have a week number of 52 (or 53 for a leap year).

Examples

iex> s = Explorer.Series.from_list([~D[2023-01-01], ~D[2023-01-02], ~D[2023-02-01], nil])
iex> Explorer.Series.week_of_year(s)
#Explorer.Series<
  Polars[4]
  s8 [52, 1, 5, nil]
>

It can also be called on a datetime series.

iex> s = Explorer.Series.from_list(
...>   [~N[2023-01-01 00:00:00], ~N[2023-01-02 00:00:00], ~N[2023-02-01 23:59:59], nil]
...> )
iex> Explorer.Series.week_of_year(s)
#Explorer.Series<
  Polars[4]
  s8 [52, 1, 5, nil]
>
@spec year(t()) :: t()

Returns the year number in the calendar date.

Examples

iex> s = Explorer.Series.from_list([~D[2023-01-15], ~D[2022-02-16], ~D[2021-03-20], nil])
iex> Explorer.Series.year(s)
#Explorer.Series<
  Polars[4]
  s32 [2023, 2022, 2021, nil]
>

It can also be called on a datetime series.

iex> s = Explorer.Series.from_list([~N[2023-01-15 00:00:00], ~N[2022-02-16 23:59:59.999999], ~N[2021-03-20 12:00:00], nil])
iex> Explorer.Series.year(s)
#Explorer.Series<
  Polars[4]
  s32 [2023, 2022, 2021, nil]
>

Functions: Float ops

@spec acos(series :: t()) :: t()

Computes the the arccosine of a number. The resultant series is going to be of dtype {:f, 64}, in radians, with values between 0 and pi.

Supported dtype

  • {:f, 32}
  • {:f, 64}

Examples

iex> s = [1.0, 0.0, -1.0, -0.7071067811865475, 0.7071067811865475] |> Explorer.Series.from_list()
iex> Explorer.Series.acos(s)
#Explorer.Series<
  Polars[5]
  f64 [0.0, 1.5707963267948966, 3.141592653589793, 2.356194490192345, 0.7853981633974484]
>
@spec asin(series :: t()) :: t()

Computes the the arcsine of a number. The resultant series is going to be of dtype {:f, 64}, in radians, with values between -pi/2 and pi/2.

Supported dtype

  • {:f, 32}
  • {:f, 64}

Examples

iex> s = [1.0, 0.0, -1.0, -0.7071067811865475, 0.7071067811865475] |> Explorer.Series.from_list()
iex> Explorer.Series.asin(s)
#Explorer.Series<
  Polars[5]
  f64 [1.5707963267948966, 0.0, -1.5707963267948966, -0.7853981633974482, 0.7853981633974482]
>
@spec atan(series :: t()) :: t()

Computes the the arctangent of a number. The resultant series is going to be of dtype {:f, 64}, in radians, with values between -pi/2 and pi/2.

Supported dtype

  • {:f, 32}
  • {:f, 64}

Examples

iex> s = [1.0, 0.0, -1.0, -0.7071067811865475, 0.7071067811865475] |> Explorer.Series.from_list()
iex> Explorer.Series.atan(s)
#Explorer.Series<
  Polars[5]
  f64 [0.7853981633974483, 0.0, -0.7853981633974483, -0.6154797086703873, 0.6154797086703873]
>
@spec ceil(t()) :: t()

Ceil floating point series to highest integers smaller or equal to the float value.

Examples

iex> s = Explorer.Series.from_list([1.124993, 2.555321, 3.995001])
iex> Explorer.Series.ceil(s)
#Explorer.Series<
  Polars[3]
  f64 [2.0, 3.0, 4.0]
>
@spec cos(series :: t()) :: t()

Computes the the cosine of a number (in radians). The resultant series is going to be of dtype {:f, 64}, with values between 1 and -1.

Supported dtype

  • {:f, 32}
  • {:f, 64}

Examples

iex> pi = :math.pi()
iex> s = [-pi * 3/2, -pi, -pi / 2, -pi / 4, 0, pi / 4, pi / 2, pi, pi * 3/2] |> Explorer.Series.from_list()
iex> Explorer.Series.cos(s)
#Explorer.Series<
  Polars[9]
  f64 [-1.8369701987210297e-16, -1.0, 6.123233995736766e-17, 0.7071067811865476, 1.0, 0.7071067811865476, 6.123233995736766e-17, -1.0, -1.8369701987210297e-16]
>
@spec floor(t()) :: t()

Floor floating point series to lowest integers smaller or equal to the float value.

Examples

iex> s = Explorer.Series.from_list([1.124993, 2.555321, 3.995001])
iex> Explorer.Series.floor(s)
#Explorer.Series<
  Polars[3]
  f64 [1.0, 2.0, 3.0]
>
@spec is_finite(t()) :: t()

Returns a mask of finite values.

Examples

iex> s1 = Explorer.Series.from_list([1, 2, 0, nil])
iex> s2 = Explorer.Series.from_list([0, 2, 0, nil])
iex> s3 = Explorer.Series.divide(s1, s2)
iex> Explorer.Series.is_finite(s3)
#Explorer.Series<
  Polars[4]
  boolean [false, true, false, nil]
>
@spec is_infinite(t()) :: t()

Returns a mask of infinite values.

Examples

iex> s1 = Explorer.Series.from_list([1, -1, 2, 0, nil])
iex> s2 = Explorer.Series.from_list([0, 0, 2, 0, nil])
iex> s3 = Explorer.Series.divide(s1, s2)
iex> Explorer.Series.is_infinite(s3)
#Explorer.Series<
  Polars[5]
  boolean [true, true, false, false, nil]
>
@spec is_nan(t()) :: t()

Returns a mask of nan values.

Examples

iex> s1 = Explorer.Series.from_list([1, 2, 0, nil])
iex> s2 = Explorer.Series.from_list([0, 2, 0, nil])
iex> s3 = Explorer.Series.divide(s1, s2)
iex> Explorer.Series.is_nan(s3)
#Explorer.Series<
  Polars[4]
  boolean [false, false, true, nil]
>
@spec round(t(), non_neg_integer()) :: t()

Round floating point series to given decimal places.

Examples

iex> s = Explorer.Series.from_list([1.124993, 2.555321, 3.995001])
iex> Explorer.Series.round(s, 2)
#Explorer.Series<
  Polars[3]
  f64 [1.12, 2.56, 4.0]
>
@spec sin(series :: t()) :: t()

Computes the the sine of a number (in radians). The resultant series is going to be of dtype {:f, 64}, with values between 1 and -1.

Supported dtype

  • {:f, 32}
  • {:f, 64}

Examples

iex> pi = :math.pi()
iex> s = [-pi * 3/2, -pi, -pi / 2, -pi / 4, 0, pi / 4, pi / 2, pi, pi * 3/2] |> Explorer.Series.from_list()
iex> Explorer.Series.sin(s)
#Explorer.Series<
  Polars[9]
  f64 [1.0, -1.2246467991473532e-16, -1.0, -0.7071067811865475, 0.0, 0.7071067811865475, 1.0, 1.2246467991473532e-16, -1.0]
>
@spec tan(series :: t()) :: t()

Computes the tangent of a number (in radians). The resultant series is going to be of dtype {:f, 64}.

Supported dtype

  • {:f, 32}
  • {:f, 64}

Examples

iex> pi = :math.pi()
iex> s = [-pi * 3/2, -pi, -pi / 2, -pi / 4, 0, pi / 4, pi / 2, pi, pi * 3/2] |> Explorer.Series.from_list()
iex> Explorer.Series.tan(s)
#Explorer.Series<
  Polars[9]
  f64 [-5443746451065123.0, 1.2246467991473532e-16, -1.633123935319537e16, -0.9999999999999999, 0.0, 0.9999999999999999, 1.633123935319537e16, -1.2246467991473532e-16, 5443746451065123.0]
>

Functions: String ops

Link to this function

contains(series, pattern)

View Source
@spec contains(t(), String.t()) :: t()

Detects whether a string contains a substring.

Examples

iex> s = Explorer.Series.from_list(["abc", "def", "bcd"])
iex> Explorer.Series.contains(s, "bc")
#Explorer.Series<
  Polars[3]
  boolean [true, false, true]
>
@spec downcase(t()) :: t()

Converts all characters to lowercase.

Examples

iex> s = Explorer.Series.from_list(["ABC", "DEF", "BCD"])
iex> Explorer.Series.downcase(s)
#Explorer.Series<
  Polars[3]
  string ["abc", "def", "bcd"]
>
Link to this function

json_decode(series, dtype)

View Source
@spec json_decode(t(), dtype()) :: t()

Decodes a string series containing valid JSON according to dtype.

Examples

iex> s = Series.from_list(["1"])
iex> Series.json_decode(s, {:s, 64})
#Explorer.Series<
  Polars[1]
  s64 [1]
>

iex> s = Series.from_list(["{\"a\":1}"])
iex> Series.json_decode(s, {:struct, [{"a", {:s, 64}}]})
#Explorer.Series<
  Polars[1]
  struct[1] [%{"a" => 1}]
>

If the decoded value does not match the given dtype, nil is returned for the given entry:

iex> s = Series.from_list(["\"1\""])
iex> Series.json_decode(s, {:s, 64})
#Explorer.Series<
  Polars[1]
  s64 [nil]
>

It raises an exception if the string is invalid JSON.

Link to this function

json_path_match(series, json_path)

View Source
@spec json_path_match(t(), String.t()) :: t()

Extracts a string series using a json_path from a series.

Examples

iex> s = Series.from_list(["{\"a\":1}", "{\"a\":2}"])
iex> Series.json_path_match(s, "$.a")
#Explorer.Series<
  Polars[2]
  string ["1", "2"]
>

If json_path is not found or if the string is invalid JSON or nil, nil is returned for the given entry:

iex> s = Series.from_list(["{\"a\":1}", nil, "{\"a\":2}"])
iex> Series.json_path_match(s, "$.b")
#Explorer.Series<
  Polars[3]
  string [nil, nil, nil]
>

It raises an exception if the json_path is invalid.

@spec lstrip(t()) :: t()

Returns a string series where all leading Unicode whitespaces have been removed.

Examples

iex> s = Explorer.Series.from_list(["  abc", "def  ", "  bcd"])
iex> Explorer.Series.lstrip(s)
#Explorer.Series<
  Polars[3]
  string ["abc", "def  ", "bcd"]
>
@spec lstrip(t(), String.t()) :: t()

Returns a string series where all leading examples of the provided string have been removed.

Where multiple characters are provided, all combinations of this set of characters will be stripped

Examples

iex> s = Explorer.Series.from_list(["$1", "$$200$$", "$$$3000$"])
iex> Explorer.Series.lstrip(s, "$")
#Explorer.Series<
  Polars[3]
  string ["1", "200$$", "3000$"]
>

iex> s = Explorer.Series.from_list(["abc", "adefa", "bcda"])
iex> Explorer.Series.lstrip(s, "ab")
#Explorer.Series<
  Polars[3]
  string ["c", "defa", "cda"]
>
Link to this function

replace(series, pattern, replacement)

View Source
@spec replace(t(), binary(), binary()) :: t()

Replaces all occurences of pattern with replacement in string series.

Both pattern and replacement must be of type string.

Examples

iex> series = Explorer.Series.from_list(["1,200", "1,234,567", "asdf", nil])
iex> Explorer.Series.replace(series, ",", "")
#Explorer.Series<
  Polars[4]
  string ["1200", "1234567", "asdf", nil]
>
@spec rstrip(t()) :: t()

Returns a string series where all trailing Unicode whitespaces have been removed.

Examples

iex> s = Explorer.Series.from_list(["  abc", "def  ", "  bcd"])
iex> Explorer.Series.rstrip(s)
#Explorer.Series<
  Polars[3]
  string ["  abc", "def", "  bcd"]
>
@spec rstrip(t(), String.t()) :: t()

Returns a string series where all trailing examples of the provided string have been removed.

Where multiple characters are provided, all combinations of this set of characters will be stripped

Examples

iex> s = Explorer.Series.from_list(["__abc__", "def_", "__bcd_"])
iex> Explorer.Series.rstrip(s, "_")
#Explorer.Series<
  Polars[3]
  string ["__abc", "def", "__bcd"]
>

iex> s = Explorer.Series.from_list(["abc", "adefa", "bcdabaaa"])
iex> Explorer.Series.rstrip(s, "ab")
#Explorer.Series<
  Polars[3]
  string ["abc", "adef", "bcd"]
>
@spec split(t(), String.t()) :: t()

Split the string by a substring.

Examples

iex> s = Series.from_list(["1", "1|2"])
iex> Series.split(s, "|")
#Explorer.Series<
  Polars[2]
  list[string] [["1"], ["1", "2"]]
>
@spec strip(t()) :: t()

Returns a string series where all leading and trailing Unicode whitespaces have been removed.

Examples

iex> s = Explorer.Series.from_list(["  abc", "def  ", "  bcd   "])
iex> Explorer.Series.strip(s)
#Explorer.Series<
  Polars[3]
  string ["abc", "def", "bcd"]
>
@spec strip(t(), String.t()) :: t()

Returns a string series where all leading and trailing examples of the provided string have been removed.

Where multiple characters are provided, all combinations of this set of characters will be stripped

Examples

iex> s = Explorer.Series.from_list(["£123", "1.00£", "£1.00£"])
iex> Explorer.Series.strip(s, "£")
#Explorer.Series<
  Polars[3]
  string ["123", "1.00", "1.00"]
>

iex> s = Explorer.Series.from_list(["abc", "adefa", "bcda"])
iex> Explorer.Series.strip(s, "ab")
#Explorer.Series<
  Polars[3]
  string ["c", "def", "cd"]
>
Link to this function

substring(series, offset)

View Source
@spec substring(t(), integer()) :: t()

Returns a string sliced from the offset to the end of the string, supporting negative indexing

Examples

iex> s = Explorer.Series.from_list(["earth", "mars", "neptune"])
iex> Explorer.Series.substring(s, -3)
#Explorer.Series<
  Polars[3]
  string ["rth", "ars", "une"]
>

iex> s = Explorer.Series.from_list(["earth", "mars", "neptune"])
iex> Explorer.Series.substring(s, 1)
#Explorer.Series<
  Polars[3]
  string ["arth", "ars", "eptune"]
>
Link to this function

substring(series, offset, length)

View Source
@spec substring(t(), integer(), integer()) :: t()

Returns a string sliced from the offset to the length provided, supporting negative indexing

Examples

iex> s = Explorer.Series.from_list(["earth", "mars", "neptune"])
iex> Explorer.Series.substring(s, -3, 2)
#Explorer.Series<
  Polars[3]
  string ["rt", "ar", "un"]
>

iex> s = Explorer.Series.from_list(["earth", "mars", "neptune"])
iex> Explorer.Series.substring(s, 1, 5)
#Explorer.Series<
  Polars[3]
  string ["arth", "ars", "eptun"]
>

iex> d = Explorer.Series.from_list(["こんにちは世界", "مرحبًا", "안녕하세요"])
iex> Explorer.Series.substring(d, 1, 3)
#Explorer.Series<
  Polars[3]
  string ["んにち", "رحب", "녕하세"]
>
@spec upcase(t()) :: t()

Converts all characters to uppercase.

Examples

iex> s = Explorer.Series.from_list(["abc", "def", "bcd"])
iex> Explorer.Series.upcase(s)
#Explorer.Series<
  Polars[3]
  string ["ABC", "DEF", "BCD"]
>

Functions: List ops

@spec join(t(), String.t()) :: t()

Join all string items in a sublist and place a separator between them.

Examples

iex> s = Series.from_list([["1"], ["1", "2"]])
iex> Series.join(s, "|")
#Explorer.Series<
  Polars[2]
  string ["1", "1|2"]
>
@spec lengths(t()) :: t()

Calculates the length of each list in a list series.

Examples

iex> s = Series.from_list([[1], [1, 2]])
iex> Series.lengths(s)
#Explorer.Series<
  Polars[2]
  u32 [1, 2]
>
@spec member?(t(), Explorer.Backend.Series.valid_types()) :: t()

Checks for the presence of a value in a list series.

Examples

iex> s = Series.from_list([[1], [1, 2]])
iex> Series.member?(s, 2)
#Explorer.Series<
  Polars[2]
  boolean [false, true]
>

Functions: Struct ops

@spec field(t(), String.t() | atom()) :: t()

Extracts a field from a struct series

The field can be an atom or string.

Examples

iex> s = Series.from_list([%{a: 1}, %{a: 2}])
iex> Series.field(s, :a)
#Explorer.Series<
  Polars[2]
  s64 [1, 2]
>

iex> s = Series.from_list([%{a: 1}, %{a: 2}])
iex> Series.field(s, "a")
#Explorer.Series<
  Polars[2]
  s64 [1, 2]
>

Functions: Introspection

@spec categories(series :: t()) :: t()

Return a series with the category names of a categorical series.

Each category has the index equal to its position. No order for the categories is guaranteed.

Examples

iex> s = Explorer.Series.from_list(["a", "b", "c", nil, "a", "c"], dtype: :category)
iex> Explorer.Series.categories(s)
#Explorer.Series<
  Polars[3]
  string ["a", "b", "c"]
>

iex> s = Explorer.Series.from_list(["c", "a", "b"], dtype: :category)
iex> Explorer.Series.categories(s)
#Explorer.Series<
  Polars[3]
  string ["c", "a", "b"]
>
@spec dtype(series :: t()) :: dtype()

Returns the data type of the series.

See the moduledoc for all supported dtypes.

Examples

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.dtype(s)
{:s, 64}

iex> s = Explorer.Series.from_list(["a", nil, "b", "c"])
iex> Explorer.Series.dtype(s)
:string
@spec iotype(series :: t()) :: {:s | :u | :f, non_neg_integer()} | :none

Returns the type of the underlying fixed-width binary representation.

It returns something in the shape of {atom(), bits_size} or :none. It is often used in conjunction with to_iovec/1 and to_binary/1.

The possible iotypes are:

  • :u for unsigned integers.
  • :s for signed integers.
  • :f for floats.

Examples

iex> s = Explorer.Series.from_list([1, 2, 3, 4])
iex> Explorer.Series.iotype(s)
{:s, 64}

iex> s = Explorer.Series.from_list([~D[1999-12-31], ~D[1989-01-01]])
iex> Explorer.Series.iotype(s)
{:s, 32}

iex> s = Explorer.Series.from_list([~T[00:00:00.000000], ~T[23:59:59.999999]])
iex> Explorer.Series.iotype(s)
{:s, 64}

iex> s = Explorer.Series.from_list([1.2, 2.3, 3.5, 4.5])
iex> Explorer.Series.iotype(s)
{:f, 64}

iex> s = Explorer.Series.from_list([true, false, true])
iex> Explorer.Series.iotype(s)
{:u, 8}

The operation returns :none for strings and binaries, as they do not provide a fixed-width binary representation:

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.iotype(s)
:none

However, if appropriate, you can convert them to categorical types, which will then return the index of each category:

iex> s = Explorer.Series.from_list(["a", "b", "c"], dtype: :category)
iex> Explorer.Series.iotype(s)
{:u, 32}
@spec size(series :: t()) :: non_neg_integer() | lazy_t()

Returns the number of elements in the series.

See also:

Examples

Basic example:

iex> s = Explorer.Series.from_list([~D[1999-12-31], ~D[1989-01-01]])
iex> Explorer.Series.size(s)
2

With lists:

iex> s = Explorer.Series.from_list([[1, 2, 3], [4, 5]])
iex> Explorer.Series.size(s)
2

Functions: Shape

Link to this function

argsort(series, opts \\ [])

View Source

Returns the indices that would sort the series.

The resultant series is going to have the {:u, 32} dtype.

Options

  • :direction - :asc or :desc, meaning "ascending" or "descending", respectively. By default it sorts in ascending order.

  • :nils - :first or :last. By default it is :last if direction is :asc, and :first otherwise.

  • :parallel - boolean. Whether to parallelize the sorting. By default it is true.

  • :stable - boolean. Determines if the sorting is stable (ties are guaranteed to maintain their order) or not. Unstable sorting may be more performant. By default it is false.

Examples

iex> s = Explorer.Series.from_list([9, 3, 7, 1])
iex> Explorer.Series.argsort(s)
#Explorer.Series<
  Polars[4]
  u32 [3, 1, 2, 0]
>

iex> s = Explorer.Series.from_list([9, 3, 7, 1])
iex> Explorer.Series.argsort(s, direction: :desc)
#Explorer.Series<
  Polars[4]
  u32 [0, 2, 1, 3]
>
@spec at(series :: t(), idx :: integer()) :: any()

Returns the value of the series at the given index.

This function will raise an error in case the index is out of bounds.

Examples

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.at(s, 2)
"c"

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.at(s, 4)
** (ArgumentError) index 4 out of bounds for series of size 3
Link to this function

at_every(series, every_n)

View Source
@spec at_every(series :: t(), every_n :: integer()) :: t()

Takes every nth value in this series, returned as a new series.

Examples

iex> s = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.at_every(s, 2)
#Explorer.Series<
  Polars[5]
  s64 [1, 3, 5, 7, 9]
>

If n is bigger than the size of the series, the result is a new series with only the first value of the supplied series.

iex> s = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.at_every(s, 20)
#Explorer.Series<
  Polars[1]
  s64 [1]
>
@spec concat([t()]) :: t()

Concatenate one or more series.

Type promotion may happen between numeric series or null series. All other dtypes must match.

Examples

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> s2 = Explorer.Series.from_list([4, 5, 6])
iex> Explorer.Series.concat([s1, s2])
#Explorer.Series<
  Polars[6]
  s64 [1, 2, 3, 4, 5, 6]
>

iex> s1 = Explorer.Series.from_list([1, 2, 3])
iex> s2 = Explorer.Series.from_list([4.0, 5.0, 6.4])
iex> Explorer.Series.concat([s1, s2])
#Explorer.Series<
  Polars[6]
  f64 [1.0, 2.0, 3.0, 4.0, 5.0, 6.4]
>
@spec concat(s1 :: t(), s2 :: t()) :: t()

Concatenate two series.

concat(s1, s2) is equivalent to concat([s1, s2]).

Returns the unique values of the series.

Examples

iex> s = [1, 1, 2, 2, 3, 3] |> Explorer.Series.from_list()
iex> Explorer.Series.distinct(s)
#Explorer.Series<
  Polars[3]
  s64 [1, 2, 3]
>
@spec first(series :: t()) :: any()

Returns the first element of the series.

Examples

iex> s = 1..100 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.first(s)
1
@spec format([t() | String.t()]) :: t()

Returns a string series with all values concatenated.

Examples

iex> s1 = Explorer.Series.from_list(["a", "b", "c"])
iex> s2 = Explorer.Series.from_list(["d", "e", "f"])
iex> s3 = Explorer.Series.from_list(["g", "h", "i"])
iex> Explorer.Series.format([s1, s2, s3])
#Explorer.Series<
  Polars[3]
  string ["adg", "beh", "cfi"]
>

iex> s1 = Explorer.Series.from_list(["a", "b", "c", "d"])
iex> s2 = Explorer.Series.from_list([1, 2, 3, 4])
iex> s3 = Explorer.Series.from_list([1.5, :nan, :infinity, :neg_infinity])
iex> Explorer.Series.format([s1, "/", s2, "/", s3])
#Explorer.Series<
  Polars[4]
  string ["a/1/1.5", "b/2/NaN", "c/3/inf", "d/4/-inf"]
>

iex> s1 = Explorer.Series.from_list([<<1>>, <<239, 191, 19>>], dtype: :binary)
iex> s2 = Explorer.Series.from_list([<<3>>, <<4>>], dtype: :binary)
iex> Explorer.Series.format([s1, s2])
** (RuntimeError) Polars Error: invalid utf-8 sequence
Link to this function

head(series, n_elements \\ 10)

View Source
@spec head(series :: t(), n_elements :: integer()) :: t()

Returns the first N elements of the series.

Examples

iex> s = 1..100 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.head(s)
#Explorer.Series<
  Polars[10]
  s64 [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>
@spec last(series :: t()) :: any()

Returns the last element of the series.

Examples

iex> s = 1..100 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.last(s)
100

Reverses the series order.

Example

iex> s = [1, 2, 3] |> Explorer.Series.from_list()
iex> Explorer.Series.reverse(s)
#Explorer.Series<
  Polars[3]
  s64 [3, 2, 1]
>
Link to this function

sample(series, n_or_frac, opts \\ [])

View Source
@spec sample(series :: t(), n_or_frac :: number(), opts :: Keyword.t()) :: t()

Returns a random sample of the series.

If given an integer as the second argument, it will return N samples. If given a float, it will return that proportion of the series.

Can sample with or without replace.

Options

  • :replace - If set to true, each sample will be independent and therefore values may repeat. Required to be true for n greater then the number of rows in the series or frac > 1.0. (default: false)
  • :seed - An integer to be used as a random seed. If nil, a random value between 0 and 2^64 − 1 will be used. (default: nil)
  • :shuffle - In case the sample is equal to the size of the series, shuffle tells if the resultant series should be shuffled or if it should return the same series. (default: false).

Examples

iex> s = 1..100 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.sample(s, 10, seed: 100)
#Explorer.Series<
  Polars[10]
  s64 [57, 9, 54, 62, 50, 77, 35, 88, 1, 69]
>

iex> s = 1..100 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.sample(s, 0.05, seed: 100)
#Explorer.Series<
  Polars[5]
  s64 [9, 56, 79, 28, 54]
>

iex> s = 1..5 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.sample(s, 7, seed: 100, replace: true)
#Explorer.Series<
  Polars[7]
  s64 [4, 1, 3, 4, 3, 4, 2]
>

iex> s = 1..5 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.sample(s, 1.2, seed: 100, replace: true)
#Explorer.Series<
  Polars[6]
  s64 [4, 1, 3, 4, 3, 4]
>

iex> s = 0..9 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.sample(s, 1.0, seed: 100, shuffle: false)
#Explorer.Series<
  Polars[10]
  s64 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
>

iex> s = 0..9 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.sample(s, 1.0, seed: 100, shuffle: true)
#Explorer.Series<
  Polars[10]
  s64 [7, 9, 2, 0, 4, 1, 3, 8, 5, 6]
>
@spec shift(series :: t(), offset :: integer()) :: t()

Shifts series by offset with nil values.

Positive offset shifts from first, negative offset shifts from last.

Examples

iex> s = 1..5 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.shift(s, 2)
#Explorer.Series<
  Polars[5]
  s64 [nil, nil, 1, 2, 3]
>

iex> s = 1..5 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.shift(s, -2)
#Explorer.Series<
  Polars[5]
  s64 [3, 4, 5, nil, nil]
>
Link to this function

shuffle(series, opts \\ [])

View Source
@spec shuffle(series :: t(), opts :: Keyword.t()) :: t()

Change the elements order randomly.

Options

  • :seed - An integer to be used as a random seed. If nil, a random value between 0 and 2^64 − 1 will be used. (default: nil)

Examples

iex> s = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.shuffle(s, seed: 100)
#Explorer.Series<
  Polars[10]
  s64 [8, 10, 3, 1, 5, 2, 4, 9, 6, 7]
>
@spec slice(series :: t(), indices :: [integer()] | Range.t() | t()) :: t()

Slices the elements at the given indices as a new series.

The indices may be either a list (or series) of indices or a range. A list or series of indices does not support negative numbers. Ranges may be negative on either end, which are then normalized. Note ranges in Elixir are inclusive.

Examples

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.slice(s, [0, 2])
#Explorer.Series<
  Polars[2]
  string ["a", "c"]
>

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.slice(s, 1..2)
#Explorer.Series<
  Polars[2]
  string ["b", "c"]
>

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.slice(s, -2..-1)
#Explorer.Series<
  Polars[2]
  string ["b", "c"]
>

iex> s = Explorer.Series.from_list(["a", "b", "c"])
iex> Explorer.Series.slice(s, 3..2//1)
#Explorer.Series<
  Polars[0]
  string []
>
Link to this function

slice(series, offset, size)

View Source
@spec slice(series :: t(), offset :: integer(), size :: integer()) :: t()

Returns a slice of the series, with size elements starting at offset.

Examples

iex> s = Explorer.Series.from_list([1, 2, 3, 4, 5])
iex> Explorer.Series.slice(s, 1, 2)
#Explorer.Series<
  Polars[2]
  s64 [2, 3]
>

Negative offsets count from the end of the series:

iex> s = Explorer.Series.from_list([1, 2, 3, 4, 5])
iex> Explorer.Series.slice(s, -3, 2)
#Explorer.Series<
  Polars[2]
  s64 [3, 4]
>

If the offset runs past the end of the series, the series is empty:

iex> s = Explorer.Series.from_list([1, 2, 3, 4, 5])
iex> Explorer.Series.slice(s, 10, 3)
#Explorer.Series<
  Polars[0]
  s64 []
>

If the size runs past the end of the series, the result may be shorter than the size:

iex> s = Explorer.Series.from_list([1, 2, 3, 4, 5])
iex> Explorer.Series.slice(s, -3, 4)
#Explorer.Series<
  Polars[3]
  s64 [3, 4, 5]
>
Link to this function

sort(series, opts \\ [])

View Source

Sorts the series.

See sort_by/3 for an expression-based sorting function. See sort_with/3 for a callback-based sorting function.

Options

  • :direction - :asc or :desc, meaning "ascending" or "descending", respectively. By default it sorts in ascending order.

  • :nils - :first or :last. By default it is :last if direction is :asc, and :first otherwise.

  • :parallel - boolean. Whether to parallelize the sorting. By default it is true.

  • :stable - boolean. Determines if the sorting is stable (ties are guaranteed to maintain their order) or not. Unstable sorting may be more performant. By default it is false.

Examples

iex> s = Explorer.Series.from_list([9, 3, 7, 1])
iex> Explorer.Series.sort(s)
#Explorer.Series<
  Polars[4]
  s64 [1, 3, 7, 9]
>

iex> s = Explorer.Series.from_list([9, 3, 7, 1])
iex> Explorer.Series.sort(s, direction: :desc)
#Explorer.Series<
  Polars[4]
  s64 [9, 7, 3, 1]
>
Link to this macro

sort_by(series, query, opts \\ [])

View Source (macro)

Sorts the series based on an expression.

Notice

This is a macro.

  • You must require Explorer.Series before using it.
  • You must use the special _ syntax. See the moduledoc for details.

See sort_with/3 for the callback-based version of this function.

Options

  • :direction - :asc or :desc, meaning "ascending" or "descending", respectively. By default it sorts in ascending order.

  • :nils - :first or :last. By default it is :last if direction is :asc, and :first otherwise.

  • :parallel - boolean. Whether to parallelize the sorting. By default it is true.

    Parallel sort isn't available on certain lazy operations. In those situations this option is ignored.

  • :stable - boolean. Determines if the sorting is stable (ties are guaranteed to maintain their order) or not. Unstable sorting may be more performant. By default it is false.

Examples

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.sort_by(s, remainder(_, 3))
#Explorer.Series<
  Polars[3]
  s64 [3, 1, 2]
>

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.sort_by(s, remainder(_, 3), direction: :desc)
#Explorer.Series<
  Polars[3]
  s64 [2, 1, 3]
>

iex> s = Explorer.Series.from_list([1, nil, 2, 3])
iex> Explorer.Series.sort_by(s, -2 * _, nils: :first)
#Explorer.Series<
  Polars[4]
  s64 [nil, 3, 2, 1]
>
Link to this function

sort_with(series, fun, opts \\ [])

View Source

Sorts the series based on a callback that returns a lazy series.

See sort_by/3 for the expression-based version of this function.

Options

  • :direction - :asc or :desc, meaning "ascending" or "descending", respectively. By default it sorts in ascending order.

  • :nils - :first or :last. By default it is :last if direction is :asc, and :first otherwise.

  • :parallel - boolean. Whether to parallelize the sorting. By default it is true.

    Parallel sort isn't available on certain lazy operations. In those situations this option is ignored.

  • :stable - boolean. Determines if the sorting is stable (ties are guaranteed to maintain their order) or not. Unstable sorting may be more performant. By default it is false.

Examples

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.sort_with(s, &Explorer.Series.remainder(&1, 3))
#Explorer.Series<
  Polars[3]
  s64 [3, 1, 2]
>

iex> s = Explorer.Series.from_list([1, 2, 3])
iex> Explorer.Series.sort_with(s, &Explorer.Series.remainder(&1, 3), direction: :desc)
#Explorer.Series<
  Polars[3]
  s64 [2, 1, 3]
>

iex> s = Explorer.Series.from_list([1, nil, 2, 3])
iex> Explorer.Series.sort_with(s, &Explorer.Series.multiply(-2, &1), nils: :first)
#Explorer.Series<
  Polars[4]
  s64 [nil, 3, 2, 1]
>
Link to this function

tail(series, n_elements \\ 10)

View Source
@spec tail(series :: t(), n_elements :: integer()) :: t()

Returns the last N elements of the series.

Examples

iex> s = 1..100 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.tail(s)
#Explorer.Series<
  Polars[10]
  s64 [91, 92, 93, 94, 95, 96, 97, 98, 99, 100]
>
Link to this function

unordered_distinct(series)

View Source

Returns the unique values of the series, but does not maintain order.

Faster than distinct/1.

Examples

iex> s = [1, 1, 2, 2, 3, 3] |> Explorer.Series.from_list()
iex> Explorer.Series.unordered_distinct(s)

Functions: Window

Link to this function

cumulative_max(series, opts \\ [])

View Source
@spec cumulative_max(series :: t(), opts :: Keyword.t()) :: t()

Calculates the cumulative maximum of the series.

Optionally, can accumulate in reverse.

Does not fill nil values. See fill_missing/2.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :date
  • :time
  • :datetime
  • :duration

Examples

iex> s = [1, 2, 3, 4] |> Explorer.Series.from_list()
iex> Explorer.Series.cumulative_max(s)
#Explorer.Series<
  Polars[4]
  s64 [1, 2, 3, 4]
>

iex> s = [1, 2, nil, 4] |> Explorer.Series.from_list()
iex> Explorer.Series.cumulative_max(s)
#Explorer.Series<
  Polars[4]
  s64 [1, 2, nil, 4]
>

iex> s = [~T[03:00:02.000000], ~T[02:04:19.000000], nil, ~T[13:24:56.000000]] |> Explorer.Series.from_list()
iex> Explorer.Series.cumulative_max(s)
#Explorer.Series<
  Polars[4]
  time [03:00:02.000000, 03:00:02.000000, nil, 13:24:56.000000]
>
Link to this function

cumulative_min(series, opts \\ [])

View Source
@spec cumulative_min(series :: t(), opts :: Keyword.t()) :: t()

Calculates the cumulative minimum of the series.

Optionally, can accumulate in reverse.

Does not fill nil values. See fill_missing/2.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :date
  • :time
  • :datetime
  • :duration

Examples

iex> s = [1, 2, 3, 4] |> Explorer.Series.from_list()
iex> Explorer.Series.cumulative_min(s)
#Explorer.Series<
  Polars[4]
  s64 [1, 1, 1, 1]
>

iex> s = [1, 2, nil, 4] |> Explorer.Series.from_list()
iex> Explorer.Series.cumulative_min(s)
#Explorer.Series<
  Polars[4]
  s64 [1, 1, nil, 1]
>

iex> s = [~T[03:00:02.000000], ~T[02:04:19.000000], nil, ~T[13:24:56.000000]] |> Explorer.Series.from_list()
iex> Explorer.Series.cumulative_min(s)
#Explorer.Series<
  Polars[4]
  time [03:00:02.000000, 02:04:19.000000, nil, 02:04:19.000000]
>
Link to this function

cumulative_product(series, opts \\ [])

View Source
@spec cumulative_product(series :: t(), opts :: Keyword.t()) :: t()

Calculates the cumulative product of the series.

Optionally, can accumulate in reverse.

Does not fill nil values. See fill_missing/2.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}

Examples

iex> s = [1, 2, 3, 2] |> Explorer.Series.from_list()
iex> Explorer.Series.cumulative_product(s)
#Explorer.Series<
  Polars[4]
  s64 [1, 2, 6, 12]
>

iex> s = [1, 2, nil, 4] |> Explorer.Series.from_list()
iex> Explorer.Series.cumulative_product(s)
#Explorer.Series<
  Polars[4]
  s64 [1, 2, nil, 8]
>
Link to this function

cumulative_sum(series, opts \\ [])

View Source
@spec cumulative_sum(series :: t(), opts :: Keyword.t()) :: t()

Calculates the cumulative sum of the series.

Optionally, can accumulate in reverse.

Does not fill nil values. See fill_missing/2.

Supported dtypes

  • floats: {:f, 32} and {:f, 64}
  • integers: {:s, 8}, {:s, 16}, {:s, 32}, {:s, 64}, {:u, 8}, {:u, 16}, {:u, 32} and {:u, 64}
  • :boolean

Examples

iex> s = [1, 2, 3, 4] |> Explorer.Series.from_list()
iex> Explorer.Series.cumulative_sum(s)
#Explorer.Series<
  Polars[4]
  s64 [1, 3, 6, 10]
>

iex> s = [1, 2, nil, 4] |> Explorer.Series.from_list()
iex> Explorer.Series.cumulative_sum(s)
#Explorer.Series<
  Polars[4]
  s64 [1, 3, nil, 7]
>
Link to this function

ewm_mean(series, opts \\ [])

View Source

Calculate the exponentially weighted moving average, given smoothing factor alpha.

Options

  • :alpha - Optional smoothing factor which specifies the importance given to most recent observations. It is a value such that, 0 < alpha <= 1. Defaults to 0.5.

  • :adjust - If set to true, it corrects the bias introduced by smoothing process. Defaults to true.

  • :min_periods - The number of values in the window that should be non-nil before computing a result. Defaults to 1.

  • :ignore_nils - If set to true, it ignore nulls in the calculation. Defaults to true.

Examples

iex> s = 1..5 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.ewm_mean(s)
#Explorer.Series<
  Polars[5]
  f64 [1.0, 1.6666666666666667, 2.4285714285714284, 3.2666666666666666, 4.161290322580645]
>

iex> s = 1..5 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.ewm_mean(s, alpha: 0.1)
#Explorer.Series<
  Polars[5]
  f64 [1.0, 1.5263157894736843, 2.070110701107011, 2.6312881651642916, 3.2097140484969833]
>
Link to this function

ewm_standard_deviation(series, opts \\ [])

View Source

Calculate the exponentially weighted moving standard deviation, given smoothing factor alpha.

Options

  • :alpha - Optional smoothing factor which specifies the importance given to most recent observations. It is a value such that, 0 < alpha <= 1. Defaults to 0.5.

  • :adjust - If set to true, it corrects the bias introduced by smoothing process. Defaults to true.

  • :bias - If set to false, it corrects the estimate to be statistically unbiased. Defaults to false.

  • :min_periods - The number of values in the window that should be non-nil before computing a result. Defaults to 1.

  • :ignore_nils - If set to true, it ignore nulls in the calculation. Defaults to true.

Examples

iex> s = 1..5 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.ewm_standard_deviation(s)
#Explorer.Series<
  Polars[5]
  f64 [0.0, 0.7071067811865476, 0.9636241116594314, 1.1771636613972951, 1.3452425132127066]
>

iex> s = 1..5 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.ewm_standard_deviation(s, alpha: 0.1)
#Explorer.Series<
  Polars[5]
  f64 [0.0, 0.7071067811865476, 0.9990770648702808, 1.2879021599718157, 1.5741638698820746]
>
Link to this function

ewm_variance(series, opts \\ [])

View Source

Calculate the exponentially weighted moving variance, given smoothing factor alpha.

Options

  • :alpha - Optional smoothing factor which specifies the importance given to most recent observations. It is a value such that, 0 < alpha <= 1. Defaults to 0.5.

  • :adjust - If set to true, it corrects the bias introduced by smoothing process. Defaults to true.

  • :bias - If set to false, it corrects the estimate to be statistically unbiased. Defaults to false.

  • :min_periods - The number of values in the window that should be non-nil before computing a result. Defaults to 1.

  • :ignore_nils - If set to true, it ignore nulls in the calculation. Defaults to true.

Examples

iex> s = 1..5 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.ewm_variance(s)
#Explorer.Series<
  Polars[5]
  f64 [0.0, 0.5, 0.9285714285714284, 1.385714285714286, 1.8096774193548393]
>

iex> s = 1..5 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.ewm_variance(s, alpha: 0.1)
#Explorer.Series<
  Polars[5]
  f64 [0.0, 0.5, 0.9981549815498153, 1.6586919736600685, 2.4779918892421087]
>
Link to this function

fill_missing(series, value)

View Source
@spec fill_missing(
  t(),
  :forward
  | :backward
  | :max
  | :min
  | :mean
  | :nan
  | :infinity
  | :neg_infinity
  | Explorer.Backend.Series.valid_types()
) :: t()

Fill missing values with the given strategy. If a scalar value is provided instead of a strategy atom, nil will be replaced with that value. It must be of the same dtype as the series.

Strategies

  • :forward - replace nil with the previous value
  • :backward - replace nil with the next value
  • :max - replace nil with the series maximum
  • :min - replace nil with the series minimum
  • :mean - replace nil with the series mean
  • :nan (float only) - replace nil with NaN

Examples

iex> s = Explorer.Series.from_list([1, 2, nil, 4])
iex> Explorer.Series.fill_missing(s, :forward)
#Explorer.Series<
  Polars[4]
  s64 [1, 2, 2, 4]
>

iex> s = Explorer.Series.from_list([1, 2, nil, 4])
iex> Explorer.Series.fill_missing(s, :backward)
#Explorer.Series<
  Polars[4]
  s64 [1, 2, 4, 4]
>

iex> s = Explorer.Series.from_list([1, 2, nil, 4])
iex> Explorer.Series.fill_missing(s, :max)
#Explorer.Series<
  Polars[4]
  s64 [1, 2, 4, 4]
>

iex> s = Explorer.Series.from_list([1, 2, nil, 4])
iex> Explorer.Series.fill_missing(s, :min)
#Explorer.Series<
  Polars[4]
  s64 [1, 2, 1, 4]
>

iex> s = Explorer.Series.from_list([1, 2, nil, 4])
iex> Explorer.Series.fill_missing(s, :mean)
#Explorer.Series<
  Polars[4]
  s64 [1, 2, 2, 4]
>

Values that belong to the series itself can also be added as missing:

iex> s = Explorer.Series.from_list([1, 2, nil, 4])
iex> Explorer.Series.fill_missing(s, 3)
#Explorer.Series<
  Polars[4]
  s64 [1, 2, 3, 4]
>

iex> s = Explorer.Series.from_list(["a", "b", nil, "d"])
iex> Explorer.Series.fill_missing(s, "c")
#Explorer.Series<
  Polars[4]
  string ["a", "b", "c", "d"]
>

Mismatched types will raise:

iex> s = Explorer.Series.from_list([1, 2, nil, 4])
iex> Explorer.Series.fill_missing(s, "foo")
** (ArgumentError) cannot invoke Explorer.Series.fill_missing/2 with mismatched dtypes: {:s, 64} and "foo"

Floats in particular accept missing values to be set to NaN, Inf, and -Inf:

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, 4.0])
iex> Explorer.Series.fill_missing(s, :nan)
#Explorer.Series<
  Polars[4]
  f64 [1.0, 2.0, NaN, 4.0]
>

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, 4.0])
iex> Explorer.Series.fill_missing(s, :infinity)
#Explorer.Series<
  Polars[4]
  f64 [1.0, 2.0, Inf, 4.0]
>

iex> s = Explorer.Series.from_list([1.0, 2.0, nil, 4.0])
iex> Explorer.Series.fill_missing(s, :neg_infinity)
#Explorer.Series<
  Polars[4]
  f64 [1.0, 2.0, -Inf, 4.0]
>
Link to this function

window_max(series, window_size, opts \\ [])

View Source

Calculate the rolling max, given a window size and optional list of weights.

Options

  • :weights - An optional list of weights with the same length as the window that will be multiplied elementwise with the values in the window. Defaults to nil.

  • :min_periods - The number of values in the window that should be non-nil before computing a result. If nil, it will be set equal to window size. Defaults to 1.

  • :center - Set the labels at the center of the window. Defaults to false.

Examples

iex> s = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.window_max(s, 4)
#Explorer.Series<
  Polars[10]
  s64 [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
>

iex> s = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.window_max(s, 2, weights: [1.0, 2.0])
#Explorer.Series<
  Polars[10]
  f64 [1.0, 4.0, 6.0, 8.0, 10.0, 12.0, 14.0, 16.0, 18.0, 20.0]
>
Link to this function

window_mean(series, window_size, opts \\ [])

View Source

Calculate the rolling mean, given a window size and optional list of weights.

Options

  • :weights - An optional list of weights with the same length as the window that will be multiplied elementwise with the values in the window. Defaults to nil.

  • :min_periods - The number of values in the window that should be non-nil before computing a result. If nil, it will be set equal to window size. Defaults to 1.

  • :center - Set the labels at the center of the window. Defaults to false.

Examples

iex> s = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.window_mean(s, 4)
#Explorer.Series<
  Polars[10]
  f64 [1.0, 1.5, 2.0, 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5]
>

iex> s = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.window_mean(s, 2, weights: [0.25, 0.75])
#Explorer.Series<
  Polars[10]
  f64 [0.25, 1.75, 2.75, 3.75, 4.75, 5.75, 6.75, 7.75, 8.75, 9.75]
>

iex> s = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.window_mean(s, 2, weights: [0.25, 0.75], min_periods: nil)
#Explorer.Series<
  Polars[10]
  f64 [nil, 1.75, 2.75, 3.75, 4.75, 5.75, 6.75, 7.75, 8.75, 9.75]
>
Link to this function

window_median(series, window_size, opts \\ [])

View Source

Calculate the rolling median, given a window size and optional list of weights.

Options

  • :weights - An optional list of weights with the same length as the window that will be multiplied elementwise with the values in the window. Defaults to nil.

  • :min_periods - The number of values in the window that should be non-nil before computing a result. If nil, it will be set equal to window size. Defaults to 1.

  • :center - Set the labels at the center of the window. Defaults to false.

Examples

iex> s = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.window_median(s, 4)
#Explorer.Series<
  Polars[10]
  f64 [1.0, 1.5, 2.0, 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5]
>

iex> s = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.window_median(s, 2, weights: [0.25, 0.75])
#Explorer.Series<
  Polars[10]
  f64 [1.5, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5, 9.5]
>

iex> s = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.window_median(s, 2, weights: [0.25, 0.75], min_periods: nil)
#Explorer.Series<
  Polars[10]
  f64 [nil, 1.5, 2.5, 3.5, 4.5, 5.5, 6.5, 7.5, 8.5, 9.5]
>
Link to this function

window_min(series, window_size, opts \\ [])

View Source

Calculate the rolling min, given a window size and optional list of weights.

Options

  • :weights - An optional list of weights with the same length as the window that will be multiplied elementwise with the values in the window. Defaults to nil.

  • :min_periods - The number of values in the window that should be non-nil before computing a result. If nil, it will be set equal to window size. Defaults to 1.

  • :center - Set the labels at the center of the window. Defaults to false.

Examples

iex> s = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.window_min(s, 4)
#Explorer.Series<
  Polars[10]
  s64 [1, 1, 1, 1, 2, 3, 4, 5, 6, 7]
>

iex> s = 1..10 |> Enum.to_list() |> Explorer.Series.from_list()
iex> Explorer.Series.window_min(s, 2, weights: [1.0, 2.0])
#Explorer.Series<
  Polars[10]
  f64 [1.0, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0]
>
Link to this function

window_standard_deviation(series, window_size, opts \\ [])

View Source

Calculate the rolling standard deviation, given a window size and optional list of weights.

Options

  • :weights - An optional list of weights with the same length as the window that will be multiplied elementwise with the values in the window. Defaults to nil.

  • :min_periods - The number of values in the window that should be non-nil before computing a result. If nil, it will be set equal to window size. Defaults to 1.

  • :center - Set the labels at the center of the window. Defaults to false.

Examples

iex> s = Explorer.Series.from_list([1, 2, 3, 4, 1])
iex> Explorer.Series.window_standard_deviation(s, 2)
#Explorer.Series<
  Polars[5]
  f64 [0.0, 0.7071067811865476, 0.7071067811865476, 0.7071067811865476, 2.1213203435596424]
>

iex> s = Explorer.Series.from_list([1, 2, 3, 4, 5, 6])
iex> Explorer.Series.window_standard_deviation(s, 2, weights: [0.25, 0.75