色彩映射规范化Symlognorm
演示使用规范以非线性方式将颜色映射映射到数据上。
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.colors as colors
"""
SymLogNorm: two humps, one negative and one positive, The positive
with 5-times the amplitude. Linearly, you cannot see detail in the
negative hump. Here we logarithmically scale the positive and
negative data separately.
Note that colorbar labels do not come out looking very good.
"""
N = 100
X, Y = np.mgrid[-3:3:complex(0, N), -2:2:complex(0, N)]
Z1 = np.exp(-X**2 - Y**2)
Z2 = np.exp(-(X - 1)**2 - (Y - 1)**2)
Z = (Z1 - Z2) * 2
fig, ax = plt.subplots(2, 1)
pcm = ax[0].pcolormesh(X, Y, Z,
norm=colors.SymLogNorm(linthresh=0.03, linscale=0.03,
vmin=-1.0, vmax=1.0),
cmap='RdBu_r')
fig.colorbar(pcm, ax=ax[0], extend='both')
pcm = ax[1].pcolormesh(X, Y, Z, cmap='RdBu_r', vmin=-np.max(Z))
fig.colorbar(pcm, ax=ax[1], extend='both')
plt.show()