使用matplotlib中的colorbar更新contourf

Question

这是我的测试代码。

import os
import matplotlib.pyplot as plt

import numpy as np

a = np.arange(10)
bb, cc = np.meshgrid(a, a)
u = np.random.randint(2, 4, (10, 10))
v = np.random.randint(2, 4, (10, 10))

fig = plt.figure(figsize=(10, 10))
ax = fig.add_subplot(111)
plt.subplots_adjust(left=0.07, bottom=0.01, right=0.95,
                    top=0.94, hspace=0.0, wspace=0.0)

for i in range(10):

    u = np.random.randint(2, 4, (10, 10))
    v = np.random.randint(2, 4, (10, 10))
    ws = np.sqrt(u**2 + v**2)
    cf = plt.contourf(bb, cc, ws)
    cb = plt.colorbar(cf)

    fig.canvas.update()
    fig.canvas.flush_events()

    plt.savefig('test_barb/%i.png' % i, dpi=200)
    for c in cf.collections:
        c.remove()
    cb.remove()

我发现令人困惑的是，我画的帧越多，输出的图像就越小。有什么方法可以防止这种情况发生吗？

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Answer 1

您可能希望确保颜色栏始终位于相同的轴上。为此，您可以在循环外创建一个颜色条轴(cax)，例如使用axes_divider，并始终将颜色条绘制到该轴fig.colorbar(cf, cax=cax)。

import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1.axes_divider import make_axes_locatable
import numpy as np

a = np.arange(10)
bb, cc = np.meshgrid(a, a)
u = np.random.randint(2, 4, (10, 10))
v = np.random.randint(2, 4, (10, 10))

fig = plt.figure(figsize=(6, 6))
ax = fig.add_subplot(111)

# create axes for the colorbar
cax = make_axes_locatable(ax).append_axes("right", size="5%", pad="2%")


for i in range(10):
    # clear colorbar axes
    cax.clear()
    u = np.random.randint(2, 4, (10, 10))
    v = np.random.randint(2, 4, (10, 10))
    ws = np.sqrt(u**2 + v**2)

    cf = ax.contourf(bb, cc, ws)
    # draw new colorbar in existing cax
    cb = fig.colorbar(cf, cax=cax)

    fig.canvas.update()
    fig.canvas.flush_events()

    #plt.savefig('test_barb/%i.png' % i, dpi=200)


plt.show()