Matplotlib：contourlevels作为colorbar中的行

Question

I'm plotting some 2D data with Matplotlib once as pcolor() , then superposing this with contour() .

When I use colorbar() I get either one or the other of the following colorbars:

How do I make the horizontal lines for the contour levels(left) also show in the colored bar(right)?

Answer 1

Based from your revised question I get what you mean. This can still be done using add_lines . This function adds the lines from a non-filled contour plot to a colorbar. The documentation can be found here .

So, by first defining the colorbar based on your pcolor plot you can later add the lines from contour to that colorbar:

import numpy
import matplotlib.pyplot as plt
import matplotlib.mlab as mlab

#Generate data
delta = 0.025

x = numpy.arange(-3.0, 3.0, delta)
y = numpy.arange(-2.0, 2.0, delta)

X, Y = numpy.meshgrid(x, y)

Z1 = mlab.bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)
Z2 = mlab.bivariate_normal(X, Y, 1.5, 0.5, 1, 1)
# difference of Gaussians
Z = 10.0 * (Z2 - Z1)

#Plot
fig = plt.figure()
ax1 = fig.add_subplot(1, 1, 1)

PC = ax1.pcolor(X, Y, Z)
CF = ax1.contour(X, Y, Z, 50, colors = "black")

cbar = plt.colorbar(PC)
cbar.add_lines(CF)

plt.show()