Sinusoidal 2-d zoneplate plot with tanh tapering

sine_zoneplate

#!/usr/bin/env python

import numpy as np
import matplotlib.pyplot as plt
import pdb

# zoneplte

W = 96
H = 96

xv, yv = np.meshgrid(
	        np.linspace(-W/2, W/2, W), 
	        np.linspace(-H/2, H/2, H)
	     )


r = np.hypot(xv,yv)

km = 0.8*np.pi
rm = W/2
w  = rm/10


term1 = np.sin( (km * r**2) / (2 * rm) )
term2 = 0.5*np.tanh((rm - r)/w) + 0.5
#g = term1 * term2
g = term1 


plt.imshow(g, cmap=plt.cm.gray)
#plt.imshow(g)

plt.show()


#pdb.set_trace()