ContEx v0.3.0 Contex.PointPlot View Source

A simple point plot, plotting points showing y values against x values.

It is possible to specify multiple y columns with the same x column. It is not yet possible to specify multiple independent series.

The x column can either be numeric or date time data. If numeric, a Contex.ContinuousLinearScale is used to scale the values to the plot, and if date time, a Contex.TimeScale is used.

Fill colours for each y column can be specified with colours/2.

A column in the dataset can optionally be used to control the colours. See colours/2 and set_colour_col_name/2

Link to this section Summary

Specifies the label rotation value that will be applied to the bottom axis. Accepts integer values for degrees of rotation or :auto. Note that manually set rotation values other than 45 or 90 will be treated as zero. The default value is :auto, which sets the rotation to zero degrees if the number of items on the axis is greater than eight, 45 degrees otherwise.

colours(plot, colour_palette)

Set the colour palette for fill colours.

new(dataset, options \\ [])

Create a new point plot definition and apply defaults.

set_colour_col_name(plot, fill_col_name)

If a single y column is specified, it is possible to use another column to control the point colour.

set_default_scales(plot)

Sets the default scales for the plot based on its column mapping.

set_x_col_name(plot, x_col_name)

Specify which column in the dataset is used for the x values.

set_y_col_names(plot, y_col_names)

Specify which column(s) in the dataset is/are used for the y values.

Link to this section Types

t()

t() :: %Contex.PointPlot{
  axis_label_rotation: term(),
  colour_palette: term(),
  dataset: term(),
  fill_scale: term(),
  height: term(),
  mapping: term(),
  transforms: term(),
  width: term(),
  x_scale: term(),
  y_scale: term()
}

Link to this section Functions

axis_label_rotation(plot, rotation)

axis_label_rotation(t(), integer() | :auto) :: t()

colours(plot, colour_palette)

colours(t(), Contex.CategoryColourScale.colour_palette()) :: t()

Set the colour palette for fill colours.

Where multiple y columns are defined for the plot, a different colour will be used for each column.

If a single y column is defined and a colour column is defined (see set_colour_col_name/2), a different colour will be used for each unique value in the colour column.

If a single y column is defined and no colour column is defined, the first colour in the supplied colour palette will be used to plot the points.

new(dataset, options \\ [])

new(Contex.Dataset.t(), keyword()) :: t()

Create a new point plot definition and apply defaults.

If the data in the dataset is stored as a list of maps, the :series_mapping option is required. This value must be a map of the plot's :x_col and :y_cols to keys in the map, such as %{x_col: :column_a, y_cols: [:column_b, column_c]}. The :y_cols value must be a list. Optionally a :fill_col mapping can be provided, which is equivalent to set_colour_col_name/2

set_colour_col_name(plot, fill_col_name)

set_colour_col_name(t(), Contex.Dataset.column_name()) :: t()

If a single y column is specified, it is possible to use another column to control the point colour.

Note: This is ignored if there are multiple y columns.

set_default_scales(plot)

set_default_scales(t()) :: t()

Sets the default scales for the plot based on its column mapping.

set_x_col_name(plot, x_col_name)

set_x_col_name(t(), Contex.Dataset.column_name()) :: t()

Specify which column in the dataset is used for the x values.

This column must contain numeric or date time data.

set_y_col_names(plot, y_col_names)

set_y_col_names(t(), [Contex.Dataset.column_name()]) :: t()

Specify which column(s) in the dataset is/are used for the y values.

These columns must contain numeric data.

Where more than one y column is specified the colours are used to identify data from each column.