Python - Plotting colored grid based on values

Question

I have been searching here and on the net. I found somehow close questions/answers to what I want, but still couldn\'t reach to what I\'m looking for.

I have an arra

Answer 1

You can create a ListedColormap for your custom colors and color BoundaryNorms to threshold the values.

import matplotlib.pyplot as plt
from matplotlib import colors
import numpy as np

data = np.random.rand(10, 10) * 20

# create discrete colormap
cmap = colors.ListedColormap(['red', 'blue'])
bounds = [0,10,20]
norm = colors.BoundaryNorm(bounds, cmap.N)

fig, ax = plt.subplots()
ax.imshow(data, cmap=cmap, norm=norm)

# draw gridlines
ax.grid(which='major', axis='both', linestyle='-', color='k', linewidth=2)
ax.set_xticks(np.arange(-.5, 10, 1));
ax.set_yticks(np.arange(-.5, 10, 1));

plt.show()

Resulting in;

For more, you can check this matplotlib example.