Plotting bar charts with a colormap legend

问题

Consider the following:

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

y = np.array([1, 4, 3, 2, 7, 11])
colors = cm.hsv(y / float(max(y)))
plot = plt.scatter(y, y, c = y, cmap = 'hsv')
plt.clf()
plt.colorbar(plot)
plt.bar(range(len(y)), y, color = colors)
plt.show()

I want to colormap legend to appear on the top right of the graph (much smaller of course). My image at the moment looks rather clunky as the colormap is clashing somewhat with the actual bars.

Thanks.

回答1:

Following this answer:

import matplotlib.pyplot as plt
from matplotlib import cm
import numpy as np
from mpl_toolkits.axes_grid1.inset_locator import inset_axes

y = np.array([1, 4, 3, 2, 7, 11])
colors = cm.hsv(y / float(max(y)))

fig, ax = plt.subplots()
plot = ax.scatter(y, y, c = y, cmap = 'hsv')
plt.cla()
ax.bar(range(len(y)), y, color = colors)

cbaxes = inset_axes(ax, width="30%", height="3%", loc=2)
plt.colorbar(plot, cax=cbaxes, orientation='horizontal', ticks=[0,2,4,6,8,10])

I use plt.subplots to easily reference the Axes (ax). You can move the color bar and change its size by editing the last 2 lines (for instance changing loc can set which corner you want the colorbar to be in).

来源：https://stackoverflow.com/questions/64431347/plotting-bar-charts-with-a-colormap-legend