from pylab import *
from numpy import ma

xmin= -1.5*pi
xmax=  1.51*pi
ymin= -2.0
ymax=  2.0

X,Y = meshgrid( arange(xmin,xmax, pi/8),arange(ymin,ymax,.1) )
U = sin(X) * cosh(Y)
V = cos(X) * sinh(Y)

figure()
#M = sqrt(pow(U, 2) + pow(V, 2)) # color by abs
M = arctan(V/U) # color by angle
Q = quiver( X, Y, U, V, M, units='x', pivot='mid', width=0.022, scale=1/0.3)
#plot(X, Y, 'k,') # dots: 'k.' 'k,' ',' 's'
axis([xmin, xmax, ymin, ymax])
title("sin(z)")

plt.savefig("sin_z_vector_field_01_Pengo.svg")
show()