polar plot

Hello,

I have a problem with polar plot, if i run the following code in matplotlib 0.98.3, polar plot is drawing a extra circle to go from
angle -3.14159265 to angle 3.03753126. Is there a solution for this problem?

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import numpy as np
from matplotlib.pyplot import figure, show, rc, grid

# radar green, solid grid lines
rc('grid', color='#316931', linewidth=1, linestyle='-')
rc('xtick', labelsize=15)
rc('ytick', labelsize=15)

# force square figure and square axes looks better for polar, IMO
fig = figure(figsize=(8,8))
ax = fig.add_axes([0.1, 0.1, 0.8, 0.8], polar=True, axisbg='#d5de9c')

z = np.zeros((1,2000),complex)
z.real = 0.2
z.imag = np.arange(-50,50,0.05)
gamma_r = np.transpose((z-1)/(z+1))

ax.plot(np.angle(gamma_r), np.abs(gamma_r), '.-', zorder=0)
ax.set_rmax(2.0)
grid(True)

show()

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Kind regards,
Jean