Change color of heatmap labels in Python (matplotlib)

Question

I am looking to change the color of the ticklabels in my heatmap based on some condition. For example below, I would like to change the colors of ticklabels containing A as red and B as green.

I tried making a list ['red', 'green', 'red', 'green'] and pass it along the color option but no success so far. Any help would be great.

import numpy as np
import matplotlib.pyplot as plt

alpha = ['ABC', 'BDF', 'ADF', 'BCF']

data = np.random.random((4,4))

fig = plt.figure()
ax = fig.add_subplot(111)
cax = ax.matshow(data, interpolation='nearest')
fig.colorbar(cax)

ax.set_xticklabels(['']+alpha)
ax.set_yticklabels(['']+alpha)

plt.show()

tmdavison · Accepted Answer · 2015-10-30 11:34:46Z

2

You can set the text colour using set_color on the label text objects:

for l in ax.xaxis.get_ticklabels()+ax.yaxis.get_ticklabels():
    if 'A' in l.get_text():
        l.set_color('r')
    elif 'B' in l.get_text():
        l.set_color('g')

Of course, this doesn't address what happens if both A and B are present in the label (i.e. should ABC be red or green)?

answered Oct 30, 2015 at 11:34

tmdavison

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1 Comment

Gaurav Jain Over a year ago

This is perfect. Thank you so much ... the conditions do not overlap so not a problem at all.

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