matplotlib.colors.Colormap#

class matplotlib.colors.Colormap(name, N=256, *, bad=None, under=None, over=None)[source]#

Bases: object

Baseclass for all scalar to RGBA mappings.

Typically, Colormap instances are used to convert data values (floats) from the interval [0, 1] to the RGBA color that the respective Colormap represents. For scaling of data into the [0, 1] interval see matplotlib.colors.Normalize. Subclasses of matplotlib.cm.ScalarMappable make heavy use of this data -> normalize -> map-to-color processing chain.

Parameters:

namestr

The name of the colormap.

Nint

The number of RGB quantization levels.

badcolor, default: transparent

The color for invalid values (NaN or masked).

Added in version 3.11.

undercolor, default: color of the lowest value

The color for low out-of-range values.

Added in version 3.11.

overcolor, default: color of the highest value

The color for high out-of-range values.

Added in version 3.11.

__call__(X, alpha=None, bytes=False)[source]#

Parameters:

Xfloat or int or array-like

The data value(s) to convert to RGBA. For floats, X should be in the interval [0.0, 1.0] to return the RGBA values X*100 percent along the Colormap line. For integers, X should be in the interval [0, Colormap.N) to return RGBA values indexed from the Colormap with index X.

alphafloat or array-like or None

Alpha must be a scalar between 0 and 1, a sequence of such floats with shape matching X, or None.

bytesbool, default: False

If False (default), the returned RGBA values will be floats in the interval [0, 1] otherwise they will be numpy.uint8s in the interval [0, 255].

Returns:

Tuple of RGBA values if X is scalar, otherwise an array of

RGBA values with a shape of X.shape + (4, ).

colorbar_extend#

When this colormap exists on a scalar mappable and colorbar_extend is not False, colorbar creation will pick up colorbar_extend as the default value for the extend keyword in the matplotlib.colorbar.Colorbar constructor.

copy()[source]#

Return a copy of the colormap.

get_bad()[source]#

Get the color for masked values.

get_over()[source]#

Get the color for high out-of-range values.

get_under()[source]#

Get the color for low out-of-range values.

is_gray()[source]#

Return whether the colormap is grayscale.

resampled(lutsize)[source]#

Return a new colormap with lutsize entries.

reversed(name=None)[source]#

Return a reversed instance of the Colormap.

Note

This function is not implemented for the base class.

Parameters:

namestr, optional

The name for the reversed colormap. If None, the name is set to self.name + "_r".

See also

LinearSegmentedColormap.reversed

ListedColormap.reversed

set_bad(color='k', alpha=None)[source]#

[Deprecated] Set the color for masked values.

Notes

Deprecated since version 3.11: Use cmap.with_extremes(bad=...) or Colormap(bad=...) instead.

set_extremes(*, bad=None, under=None, over=None)[source]#

[Deprecated] Set the colors for masked (bad) values and, when norm.clip = False, low (under) and high (over) out-of-range values.

Notes

Deprecated since version 3.11: Use cmap.with_extremes(bad=..., under=..., over=...) or Colormap(bad=..., under=..., over=...) instead.

set_over(color='k', alpha=None)[source]#

[Deprecated] Set the color for high out-of-range values.

Notes

Deprecated since version 3.11: Use cmap.with_extremes(over=...) or Colormap(over=...) instead.

set_under(color='k', alpha=None)[source]#

[Deprecated] Set the color for low out-of-range values.

Notes

Deprecated since version 3.11: Use cmap.with_extremes(under=...) or Colormap(under=...) instead.

with_alpha(alpha)[source]#

Return a copy of the colormap with a new uniform transparency.

Parameters:

alphafloat

The alpha blending value, between 0 (transparent) and 1 (opaque).

with_extremes(*, bad=None, under=None, over=None)[source]#

Return a copy of the colormap, for which the colors for masked (bad) values and, when norm.clip = False, low (under) and high (over) out-of-range values, have been set accordingly.

Examples using matplotlib.colors.Colormap#

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Contourf demo

Contourf demo

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Create a colormap from a list of colors

Create a colormap from a list of colors

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Selecting individual colors from a colormap

Selecting individual colors from a colormap

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Lasso Demo

Lasso Demo

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Left ventricle bullseye

Left ventricle bullseye

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Customized Colorbars Tutorial

Customized Colorbars Tutorial

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Creating Colormaps in Matplotlib

Creating Colormaps in Matplotlib