在matplotlib中绘制网格图案

Question

我想绘制一个如下所示的草图，使用python和matplotlib。我想制作网格并不困难，但是如何以特定的方式为特定的方块着色？

Answer 1

N = 15 
# make an empty data set 
data = np.ones((N, N)) * np.nan 
# fill in some fake data 
for j in range(3)[::-1]: 
    data[N//2 - j : N//2 + j +1, N//2 - j : N//2 + j +1] = j 
# make a figure + axes 
fig, ax = plt.subplots(1, 1, tight_layout=True) 
# make color map 
my_cmap = matplotlib.colors.ListedColormap(['r', 'g', 'b']) 
# set the 'bad' values (nan) to be white and transparent 
my_cmap.set_bad(color='w', alpha=0) 
# draw the grid 
for x in range(N + 1): 
    ax.axhline(x, lw=2, color='k', zorder=5) 
    ax.axvline(x, lw=2, color='k', zorder=5) 
# draw the boxes 
ax.imshow(data, interpolation='none', cmap=my_cmap, extent=[0, N, 0, N], zorder=0) 
# turn off the axis labels 
ax.axis('off')