Class Colorbar

lib/matplotlib/colorbar.py:210–1354

r""" Draw a colorbar in an existing Axes. Typically, colorbars are created using `.Figure.colorbar` or `.pyplot.colorbar` and associated with `.ColorizingArtist`\s (such as an `.AxesImage` generated via `~.axes.Axes.imshow`). In order to draw a colorbar not associated with othe

@_docstring.interpd
class Colorbar:
    r"""
    Draw a colorbar in an existing Axes.

    Typically, colorbars are created using `.Figure.colorbar` or
    `.pyplot.colorbar` and associated with `.ColorizingArtist`\s (such as an
    `.AxesImage` generated via `~.axes.Axes.imshow`).

    In order to draw a colorbar not associated with other elements in the
    figure, e.g. when showing a colormap by itself, one can create an empty
    `.ColorizingArtist`, or directly pass *cmap* and *norm* instead of *mappable*
    to `Colorbar`.

    Useful public methods are :meth:`set_label` and :meth:`add_lines`.

    Attributes
    ----------
    ax : `~matplotlib.axes.Axes`
        The `~.axes.Axes` instance in which the colorbar is drawn.
    lines : list
        A list of `.LineCollection` (empty if no lines were drawn).
    dividers : `.LineCollection`
        A LineCollection (empty if *drawedges* is ``False``).
    """

    n_rasterize = 50  # rasterize solids if number of colors >= n_rasterize

    def __init__(
        self, ax, mappable=None, *,
        alpha=None,
        location=None,
        extend=None,
        extendfrac=None,
        extendrect=False,
        ticks=None,
        format=None,
        values=None,
        boundaries=None,
        spacing='uniform',
        drawedges=False,
        label='',
        cmap=None, norm=None,  # redundant with *mappable*
        orientation=None, ticklocation='auto',  # redundant with *location*
    ):
        """
        Parameters
        ----------
        ax : `~matplotlib.axes.Axes`
            The `~.axes.Axes` instance in which the colorbar is drawn.

        mappable : `.ColorizingArtist`
            The mappable whose colormap and norm will be used.

            To show the colors versus index instead of on a 0-1 scale, set the
            mappable's norm to ``colors.NoNorm()``.

        alpha : float
            The colorbar transparency between 0 (transparent) and 1 (opaque).