python - matplotlib for 循环显示、保存和重绘所有图

Question

这是我的python代码，

import numpy as np
import matplotlib.pyplot as plt
from pylab import *
from matplotlib.pyplot import savefig


a = np.genfromtxt('do_cv.csv', skiprows = 1, delimiter = ',')
for i in xrange(2):
    t = a[i+1:(i+1)*60, 2]
    z = a[i+1:(i+1)*60, 3]
    est_z = a[i+1:(i+1)*60, 6]
    figure(i+1)
    plt.plot(t, z, 'bo-', t, est_z, 'go-')
    plt.xlabel('time')
    plt.ylabel('data value')
    plt.grid(True)
    plt.legend(['sample data', 'estimated sample data'])
    plt.savefig('test + str(i).png')


plt.show()

然后出现2​​个窗口，像这样，

图 2 包含图 1 的绘图，如何在第二个循环开始之前重新绘制绘图？我的文件夹中只保存了 1 个 png 文件。

如何修改我的代码并得到我想要的结果？请给我一些建议，非常感谢。

Answer 1

你应该给自己写一个辅助函数:

def my_plotter(ax, t, z, est_z):
    ln1 = ax.plot(t, z, 'bo-', label='sample data')
    ln2 = ax.plot(t, est_z, 'go-', label='estimated sample data')
    ax.xlabel('time')
    ax.ylabel('data value')
    ax.grid(True)
    ax.legend()
    return ln1 + ln2

for i in xrange(2):
    # get the data
    t = a[i+1:(i+1)*60, 2]
    z = a[i+1:(i+1)*60, 3]
    est_z = a[i+1:(i+1)*60, 6]
    # make the figure
    fig, ax = plt.subplots()
    # do the plot
    my_plotter(ax, t, z, est_Z)
    # save
    fig.savefig('test_{}.png'.format(i))

现在，如果您决定将这两个图作为子图放置，您所要做的就是:

# make one figure with 2 axes
fig, ax_lst = plt.subplots(1, 2)

for i, ax in zip(xrange(2), ax_lst):
    # get the data
    t = a[i+1:(i+1)*60, 2]
    z = a[i+1:(i+1)*60, 3]
    est_z = a[i+1:(i+1)*60, 6]
    # do the plot
    my_plotter(ax, t, z, est_Z)
# save the figure with both plots
fig.savefig('both.png')