draw a colour map with automatic gradient

colour_map.py

import matplotlib.pyplot as plt
  
# generate some example data
matrix = [[1,2,3,4,5,6,7,8,9,10],[1,1,1,1,1,1,1,1,1,1],[5,5,5,5,5,5,5,5,5,5]]

# plot the matrix as an image with an appropriate colormap
plt.imshow(matrix, aspect='auto', cmap="bwr")

# add the values
for nrow in range(0,len(matrix)):
        for ncol in range(0, len(matrix[nrow])):
                plt.text(ncol, nrow, "%.3f"%matrix[nrow][ncol], va='center', ha='center')

plt.axis('off')
plt.show()