Matplotlib: Custom colormap with three colors

Question

I would like to pass a colormap to a matplotlib.imshow to plot a NxN array where each cell can only take the values -1,0 and 1. I would like my colormap to map exactly one color (in hex code) to each value.

I just have no idea how to define a custom colormap which is not a gradation between two colors.

score 5 · Accepted Answer · edited Jun 04 '19 at 22:25

5

A solution to a very similar question was provided here. In summary ,

import matplotlib
matplotlib.colors.ListedColormap(list-of-colours)

is your friend.

edited Jun 04 '19 at 22:25

answered Oct 05 '15 at 18:19

fernando

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score 3 · Answer 2 · edited Jan 11 '16 at 21:23

3

Found the answer to my question, as fernando suggested:

import matplotlib
colorsList = [(tuple rgb color 1),(tuple rgb color 2),(tuple rgb color 3)]
CustomCmap = matplotlib.colors.ListedColormap(colorsList)

edited Jan 11 '16 at 21:23

xnx

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answered Oct 06 '15 at 10:37

Learning is a mess

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Matplotlib: Custom colormap with three colors

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