Remove deprecated 'frac' property for plotting.

user_libs/antenna_patterns/plot_fields.py

@@ -103,7 +103,7 @@ for patt in range(0, len(radii)):
 # Theta axis options
 ax.set_theta_zero_location('N')
 ax.set_theta_direction('clockwise')
-ax.set_thetagrids(np.arange(0, 360, 30), frac=1.1)
+ax.set_thetagrids(np.arange(0, 360, 30))
 
 # Radial axis options
 ax.set_rmax(0)