def get_cmap(cmap=None):
    """
    Loads a matplotlib colormap if specified or supplies the default.

    Parameters
    ----------
    cmap: string or matplotlib.colors.Colormap instance
        The name of the Matplotlib colormap to look up.

    Returns
    -------
    The desired Matplotlib colormap

    Raises
    ------
    ValueError if colormap name is not recognized by Matplotlib
    """

    if isinstance(cmap, matplotlib.colors.Colormap):
        return cmap
    if isinstance(cmap, str):
        cmap_name = cmap
    else:
        cmap_name = DEFAULT_COLOR_MAP_NAME
    return plt.get_cmap(cmap_name)
Loads a matplotlib colormap if specified or supplies the default.

    Parameters
    ----------
    cmap: string or matplotlib.colors.Colormap instance
        The name of the Matplotlib colormap to look up.

    Returns
    -------
    The desired Matplotlib colormap

    Raises
    ------
    ValueError if colormap name is not recognized by Matplotlib