Settings View Source MatrixReloaded (matrix_reloaded v2.3.0)

Documentation for Matrix Reloaded library.

This a library is focusing only on updating, rearranging, getting/dropping row/column of a matrix. Also contains a few matrix operations like addition, subtraction or multiplication. Anyway if you need make fast operations on matrices, please use Matrex library.

Each matrix is represented as a "list of lists" and functions mostly return Result. It means either tuple of {:ok, object} or {:error, "msg"} where object is either matrix or submatrix, vector or number.

Numbering of row and column of matrix starts from 0 and goes to m - 1 and n - 1 where {m, n} is dimension (size) of matrix. Similarly for a row or column vector.

In case of need, if you want to save your matrix to a file you can use package CSVlixir and then call function

def save_csv(matrix, file_name \\ "matrix.csv") do
file_name
  |> File.open([:write], fn file ->
    matrix
    |> CSVLixir.write()
    |> Enum.each(&IO.write(file, &1))
  end)
end

For example, you can choose where to save your matrix (in our case it's a tmp directory)

MatrixReloaded.Matrix.new(3, 1)
|> Result.and_then(&MatrixReloaded.Matrix.save_csv(&1, "/tmp/matrix.csv"))
# {:ok, :ok}

examples

Examples:

iex> alias MatrixReloaded.Matrix

iex> up = Matrix.diag([2, 2, 2], 1)
iex> down = Matrix.diag([2, 2, 2], -1)
iex> diag = Matrix.diag([3, 3, 3, 3])
iex> band_mat = Result.and_then_x([up, down], &Matrix.add(&1, &2))
iex> band_mat = Result.and_then_x([band_mat, diag], &Matrix.add(&1, &2))
{:ok,
  [
    [3, 2, 0, 0],
    [2, 3, 2, 0],
    [0, 2, 3, 2],
    [0, 0, 2, 3]
  ]
}

iex> ones = Matrix.new(2, 1)
iex> mat = Result.and_then_x([band_mat, ones], &Matrix.update(&1, &2, {1, 1}))
{:ok,
  [
    [3, 2, 0, 0],
    [2, 1, 1, 0],
    [0, 1, 1, 2],
    [0, 0, 2, 3]
  ]
}

iex> mat |> Result.and_then(&Matrix.get_row(&1, 4))
iex>
{:error, "You can not get row from the matrix. The row number 4 is outside of matrix!"}

iex> mat |> Result.and_then(&Matrix.get_row(&1, 3))
iex>
{:ok, [0, 0, 2, 3]}

iex(4)> mat |> Result.and_then(&Matrix.drop_col(&1, 3))
{:ok,
  [
    [3, 2, 0],
    [2, 3, 2],
    [0, 2, 3],
    [0, 0, 2]
  ]
}