PerceptualColormap

class PerceptualColormap(*args, space=None, clip=True, gamma=None, gamma1=None, gamma2=None, **kwargs)[source]

Bases: proplot.colors.ContinuousColormap

A ContinuousColormap with linear transitions across hue, saturation, and luminance rather than red, blue, and green.

Parameters

  • segmentdata (dict-like) – Dictionary containing the keys 'hue', 'saturation', 'luminance', and (optionally) 'alpha'. The key 'chroma' is treated as a synonym for 'saturation'. The shorthands 'h', 's', 'l', 'a', and 'c' are also acceptable. The key values can be callable functions that return channel values given a colormap index, or 3-column arrays indicating the coordinates and channel transitions. See LinearSegmentedColormap for a more detailed explanation.

  • name (str, optional) – The colormap name. This can also be passed as the first positional string argument. Default is '_no_name'.

  • N (int, optional) – Number of points in the colormap lookup table. Default is rc['image.lut'] = 256.

  • space ({'hsl', 'hpl', 'hcl', 'hsv'}, optional) – The hue, saturation, luminance-style colorspace to use for interpreting the channels. See this page for a full description. Default is 'hsl'.

  • clip (bool, optional) – Whether to “clip” impossible colors (i.e. truncate HCL colors with RGB channels with values greater than 1) or mask them out as gray.

  • gamma (float, optional) – Set gamma1 and gamma2 to this identical value.

  • gamma1 (float, optional) – If greater than 1, make low saturation colors more prominent. If less than 1, make high saturation colors more prominent. Similar to the HCLWizard option.

  • gamma2 (float, optional) – If greater than 1, make high luminance colors more prominent. If less than 1, make low luminance colors more prominent. Similar to the HCLWizard option.

  • alpha (float, optional) – The opacity for the entire colormap. This overrides the input opacities.

  • cyclic (bool, optional) – Whether the colormap is cyclic. If True, this changes how the leftmost and rightmost color levels are selected, and extend can only be 'neither' (a warning will be issued otherwise).

Other Parameters

**kwargs – Passed to matploitlib.colors.LinearSegmentedColormap.

Example

The below example generates a PerceptualColormap from a segmentdata dictionary that uses color names for the hue data, instead of channel values between 0 and 360.

>>> import proplot as pplt
>>> data = {
>>>     'h': [[0, 'red', 'red'], [1, 'blue', 'blue']],
>>>     's': [[0, 100, 100], [1, 100, 100]],
>>>     'l': [[0, 100, 100], [1, 20, 20]],
>>> }
>>> cmap = pplt.PerceptualColormap(data)

See also

ContinuousColormap, proplot.constructor.Colormap

Methods Summary

copy([name, segmentdata, N, alpha, gamma, ...])

Return a new colormap with relevant properties copied from this one if they were not provided as keyword arguments.

from_color(*args, **kwargs)

Return a simple monochromatic "sequential" colormap that blends from white or near-white to the input color.

from_hsl(*args, **kwargs)

Make a PerceptualColormap by specifying the hue, saturation, and luminance transitions individually.

from_list(*args[, adjust_grays])

Make a PerceptualColormap from a sequence of colors.

set_gamma([gamma, gamma1, gamma2])

Set the gamma value(s) for the luminance and saturation transitions.

to_continuous([name])

Convert the PerceptualColormap to a standard ContinuousColormap.