自动使matplotlib轴平方并等于xlim和ylim

Question

让我们说我想在matplotlib中绘制一个椭圆：

import numpy as np
import matplotlib.pyplot as plt

x =   np.sin(np.linspace(0,2*np.pi,100))
y = 2*np.cos(np.linspace(0,2*np.pi,100))

ax = plt.subplot(111)
ax.plot(x,y)
plt.show()

结果看起来像一个圆圈：

我可以通过添加五行代码来获得我想要的结果：

import numpy as np
import matplotlib.pyplot as plt

x =   np.sin(np.linspace(0,2*np.pi,100))
y = 2*np.cos(np.linspace(0,2*np.pi,100))

ax = plt.subplot(111)
ax.plot(x,y)

#make the axes square and equal
ax.set_aspect('equal')

minimum = np.min((ax.get_xlim(),ax.get_ylim()))
maximum = np.max((ax.get_xlim(),ax.get_ylim()))

ax.set_xlim(minimum*1.2,maximum*1.2)
ax.set_ylim(minimum*1.2,maximum*1.2)

plt.show()

但这看起来非常笨重。是否在matplotlib中内置了一个自动提供预期行为的函数？

Answer 1

快速谷歌把它扔了：http://matplotlib.org/examples/pylab_examples/equal_aspect_ratio.html。 不过，我自己没有测试过。

ax.set_aspect('equal', 'datalim')
ax.margins(0.1)

Answer 2

如果有用，这是 MATLAB 的类似代码：

% Make axes equal in size and lenght
% ax3 is an axe() object.
    axis (ax3,'auto')
    axis (ax3,'square')
    minimum = min(abs([ax3.XLim,ax3.YLim]));
    maximum = max(abs([ax3.XLim,ax3.YLim]));
    limit = max(minimum,maximum);
    limit = round(limit,0);
    axis(ax3,[-limit limit -limit limit]);

    ticks = [-limit:limit/5:limit];
    xticks(ax3, ticks);
    yticks(ax3,ticks);
    grid(ax3,'on')