Polar axis not showing data (matplotlib)

Question

This is my first time in drawing a polar axis plot with matplotlib and would appreciate some guidance here. I am currently trying to plot a line at theta1 (105 degrees) but I am unable to see any data printed on my polar axis plot. The image I obtained is as shown:

My script is:

import matplotlib as mpl
mpl.use('Agg')
import numpy as np
import matplotlib.pyplot as plt


fig1 = plt.figure()
ax1 = fig1.add_axes([0,0,1,1],polar=True)
theta1 = 105.968
print ("theta1= %s" %theta1)    
R1 = 1

ax1.plot(theta1, R1, lw=2.5)

plt.savefig('plot.png')

Can anyone advise me on what I am doing incorrectly? As I've used ax1.plot(theta1, R1, lw=2.5) , I expected a straight line to appear at around 106 degrees, with the line extending out at 1.0, and line width of 2.5. I've also tried to double the line width.

Answer 1

Two problems here:

• First has nothing to do with polar plots. Providing a single value to the first two arguments of plot creates a point, not a line. You would need to set some marker, marker="o" , to see this point.

  A line needs at least two points to be shown as line.

   ax.plot([x1,x2],[y1,y2]) 

• Second, angles need to be given in radiants.

   theta = np.deg2rad([105,105]) R = [0,1] ax.plot(theta, R, lw=2.5)