window

The window a plot draws in.

A 2d plot covers an interval of data on each axis and draws it into a rectangle of character cells. This module names that mapping, so that the plots can share it and the furnishings around them can read it.

• window: The intervals, the rectangle, and the conversions between data coordinates and the sub-cell grids the drawing routines work in, in both directions: where a point of the data lands, and what coordinate a given part of the grid stands for.

For the mapping from 3d data onto a plane, see matthewplotlib.camera.

window : dataclass source

The interval of data a plot covers on each axis, and the rectangle of character cells it covers them with.

Inputs:

• xrange : optional (number, number). The data coordinates at the left and the right edges of the rectangle. None if the horizontal axis carries no coordinate.
• yrange : optional (number, number). The data coordinates at the bottom and the top edges of the rectangle. None if the vertical axis carries no coordinate.
• width : int. The width of the rectangle, in character cells.
• height : int. The height of the rectangle, in character cells.

A range runs from the value at the low end of the screen axis to the value at the high end: xrange from the left edge to the right, yrange from the bottom edge to the top. Giving one descending inverts that axis, which mirrors the picture and changes nothing else.

Plots divide the rectangle in one of two ways, and a range means the same thing for both---the interval the plot covers---but the two place the limits differently within the outermost cell.

• Plots that draw points and lines into a grid of braille dots put the limits at the centres of the outermost dots, so that a point at the extreme of its data is drawn rather than landing on a boundary.
• Plots that tile the rectangle with coloured squares put the limits at the outer edges of the outermost squares, so that every square stands for an equal area.

The difference is under half a cell, and invisible to labels drawn at the edges of the rectangle.

dots(points: NDArray) -> NDArray : source

Points in the data's coordinates, as coordinates in the plot's dots.

The dot grid has two columns and four rows of dots per character cell. A dot coordinate is a position in that grid, so that its integer part selects a dot and its fractional part places the point within that dot. The data's limits land on the centres of the outermost dots.

Inputs:

• points : float[n, 2]. The points, as (x, y) pairs in data coordinates.

Returns:

• dots : float[n, 2]. The same points, as (row, column) pairs in dot coordinates, with row zero at the top of the window.

pixel_edges() -> tuple[NDArray, NDArray] : source

The data coordinates of the boundaries between the plot's pixels.

The pixel grid has one column and two rows of pixels per character cell, and the pixels tile the window's intervals exactly.

Returns:

• xedges : float[width + 1]. The boundaries from the left edge of the window to the right.
• yedges : float[2 * height + 1]. The boundaries from the bottom edge of the window to the top.

Both run in screen order, and so descend numerically wherever the corresponding range does.

pixel_centres() -> tuple[NDArray, NDArray] : source

The data coordinates at the centre of each of the plot's pixels.

Each pixel stands for the square of the plane it covers, so the coordinate that represents it is the one at its centre.

Returns:

• X : float[2 * height, width].
• Y : float[2 * height, width]. The x and the y coordinate of each pixel's centre, with row zero at the top of the window.

sample_points(endpoints: bool = False) -> NDArray : source

The (x, y) coordinate that each of the plot's pixels stands for, as a list of points to hand to a function of the plane.

Inputs:

• endpoints : bool (default: False). By default the pixels tile the window's ranges exactly and each one is represented by its own centre. If true, the coordinates are instead spread from one end of each range to the other, so that the four corner pixels stand for the four corner combinations of the ranges and the pixels reach half a pixel beyond them.

Returns:

• points : float[2 * height * width, 2]. The coordinates as (x, y) pairs, the top row of pixels first, so that reshaping the values back to [2 * height, width] puts them where they came from.