Python matplotlib polar graph

Question

I use the following code to build sin in the polar

from pylab import *
import matplotlib.pyplot as plt
from pylab import *
import numpy as np
theta = np.arange(0, 2*np.pi, .01)[1:] 

def f(x):
    return x

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

and the result:

but I want to build its symmetry, I mean like this:

how can i change theta to build this? thank.

Answer 1

Matplotblib fields allow a negative radius. So, if you need a symmetrical graph, you need to build the absolute value of sin:

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

Answer 2

Anon, you need to build the opposite value sin(theta):

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