Using matplotlib to draw color bar with distinguishable and uncontinues colors

Question

The color bar in the figure below is drawn in matlab. I am wondering if it is possible to draw the similar color bar in python/matplotlib? I need the un-smoothing

Answer 1

Use ListedColormap and BoundaryNorm:

import numpy as np
import matplotlib as mpl
from matplotlib import pyplot
data = np.floor(np.random.random((10,10)) * 6)
cmap = mpl.colors.ListedColormap(['w', 'b', 'g', 'y', '#ff8c00', 'r'])
norm = mpl.colors.BoundaryNorm([0,1,2,3,4,5,6], cmap.N)
pyplot.imshow(data, cmap=cmap, norm=norm, interpolation='none')
pyplot.colorbar()
pyplot.show()

Some examples of using ListedColormap: colorbars, multicolored lines.