matplotlib条形图渐变面色

Question

我想知道怎么给我的柱状图添加渐变的面色。我想了解从简单的单色渐变到复杂的多色渐变的用法。下面是一些示例代码：

import numpy as np
import matplotlib.pyplot as plt

plt.figure(figsize=(1,5))
plt.axis([0,1,-50,200])
plt.xticks([])
plt.yticks([-40,180])
plt.bar(left=0, width=1, bottom=-40, height=220, color='r')
plt.subplots_adjust(left=0.4, right=0.8)
plt.savefig("test.png")

Answer 1

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt

# http://matplotlib.sourceforge.net/examples/api/colorbar_only.html

fig=plt.figure(figsize=(1,5))
ax=fig.add_subplot(111)
ax.axis([0,1,-50,200])
cmap = mpl.cm.jet
norm = mpl.colors.Normalize(vmin=-40, vmax=180)
cb1 = mpl.colorbar.ColorbarBase(ax, cmap=cmap,
                                orientation='vertical',                                
                                norm=norm,
                                ticks=[-40,180]
                                )

plt.subplots_adjust(left=0.4, right=0.8)
plt.show()