python colorbar箭头设置

左侧箭头

import matplotlib.pyplot as plt
import matplotlib as mpl

fig = plt.figure(figsize=(4,3))
ax = fig.add_axes([0.05,0.5,0.8,0.1])
cmap = mpl.colors.ListedColormap(['r','g','b','c'])
cmap.set_over('0.25')
cmap.set_under('0.75')
bounds = [1,2,3,4,5]
norm = mpl.colors.BoundaryNorm(bounds,cmap.N)
cb = mpl.colorbar.ColorbarBase(ax,
                               cmap = cmap,
                               norm = norm,
                               boundaries = [0]+bounds,
                               orientation = 'horizontal',
                               extend = 'min')

效果图：

右侧箭头

import matplotlib.pyplot as plt
import matplotlib as mpl

fig = plt.figure(figsize=(4,3))
ax = fig.add_axes([0.05,0.5,0.8,0.1])
cmap = mpl.colors.ListedColormap(['r','g','b','c'])
cmap.set_over('0.25')
cmap.set_under('0.75')
bounds = [1,2,3,4,5]
norm = mpl.colors.BoundaryNorm(bounds,cmap.N)
cb = mpl.colorbar.ColorbarBase(ax,
                               cmap = cmap,
                               norm = norm,
                               boundaries = bounds+[6],
                               orientation = 'horizontal',
                               extend = 'max')

效果图：

两端箭头

import matplotlib.pyplot as plt
import matplotlib as mpl

fig = plt.figure(figsize=(4,3))
ax = fig.add_axes([0.05,0.5,0.8,0.1])
cmap = mpl.colors.ListedColormap(['r','g','b','c'])
cmap.set_over('0.25')
cmap.set_under('0.75')
bounds = [1,2,3,4,5]
norm = mpl.colors.BoundaryNorm(bounds,cmap.N)
cb = mpl.colorbar.ColorbarBase(ax,
                               cmap = cmap,
                               norm = norm,
                               boundaries = bounds+[6],
                               orientation = 'horizontal',
                               extend = 'both')

效果图：