python matplotlib极地情节

Question

I am using the following code to create a polar plot of the sinus.

import numpy as np
import matplotlib.pyplot as plt


theta = np.arange(0, 2*np.pi, .01)[1:]
plt.polar(theta, sin(theta))
plt.show()

which produces:

but I want to plot it symmetrically, like this:

How can I get the result I want?

Answer 1

The matplotlib polar allows for negative radius. So, if you want the symmetric plot you need to plot the absolute value of sin:

polar(theta, abs(sin(theta)))

Answer 2

Anon, you need to plot the opposite of sin(theta) :

plt.polar(theta, sin(theta))
plt.polar(theta, -sin(theta))