如何使用Matplotlib pyplot pcolor为绘图中的每个网格提供不同的颜色

Question

I have built some fairly simple logarithmic matplotlib scatter plots. I am happy with the results thus far, but I need to change the color of each grid area.

Current Plot:

I would like to understand how I could do the following:

I appreciate any help. Thanks.

Answer 1

Plot a small image underneath the scatter plot, with an integer indicating the tile color. You can then use pcolor to plot the image, with edgecolors to define the borders. The code below does this, with cell color defined as the maximum of cell index i, j, which happens to match your grid.

import numpy as np
import matplotlib.pyplot as plt

# define grid
nx, ny = 6, 5
x, y = np.arange(nx), np.arange(ny)
xx, yy = np.meshgrid(x, y)
z = np.maximum(xx, yy)

# create random points
npoints = 30
data_x = 10**(np.random.rand(npoints)*nx)
data_y = 10**(np.random.rand(npoints)*ny-1)

# plot grid then points
plt.pcolor(10.**x, 10.**(y-1), z, edgecolors='k')
plt.loglog(data_x, data_y, '.w')
plt.axis([1,10**5,0.1,10**3])
plt.show()

Note that you could also use zorder=n to force the scatter plot above the image.