matplotlib:如何在2D历史图中指定颜色级别 [英] matplotlib: How can you specify colour levels in a 2D historgram

问题描述

我想绘制一个包含正数和负数的2D直方图.我有以下使用pcolormesh的代码，但是我无法指定颜色级别来强制白色对应于零(即我希望我的颜色条在零附近对称).我也尝试过imshow.

I would like to plot a 2D histogram that includes both positive and negative numbers. I have the following code which uses pcolormesh but I am unable to specify the color levels to force the white color to corresponds to zero (i.e., I want my colorbar to be symmetric around zero). I've also tried imshow.

我知道您可以在plt.contour和plt.contourf中指定颜色级别，但是我找不到使用块绘制2D直方图的方法.

I know you can specify colour levels in plt.contour and plt.contourf but I can't find a way to plot the 2D histogram using blocks.

任何建议将不胜感激.

import numpy as np
import matplotlib.pyplot as plt
from matplotlib import cm as CM

fig = plt.figure()

# create an example histogram which is asymmetrical around zero
x = np.random.rand(400)
y = np.random.rand(400)    
Z, xedges, yedges = np.histogram2d(x, y, bins=10)   
Z = Z - 2.

plt.pcolormesh(xedges, yedges, Z, cmap=CM.RdBu_r)

plt.colorbar()
plt.savefig('test.png')

推荐答案

添加具有相等绝对值的vmin和vmax参数

Add vmin and vmax parameters with equal absolute values

plt.pcolormesh(xedges, yedges, Z, cmap=CM.RdBu_r, vmin=-7, vmax=7)

看看您是否喜欢结果

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