def draw_pol(map_q,map_u,nside, ampl=1):
"""Draw polarization field on current map.
Parameters
----------
map_q : map of the Q Stokes parameter
map_u : map of the U Stokes parameter
nside : nside of the displayed map
ampl : mutliplicative factor for the length of the polarization line drawn on the map
"""
f = pl.gca()
if isinstance(f, PA.HpxMollweideAxes) == False :
raise NotImplementedError('The function draw_pol can only be used with mollview()')
nb_pixels= 12* (nside**2)
factor = ampl*1/(np.sqrt(12)*nside)
map_q_grade = pixelfunc.ud_grade(map_q, nside)
map_u_grade = pixelfunc.ud_grade(map_u, nside)
for i in range(nb_pixels):
x_pix,y_pix,z_pix = P.pix2vec(nside,i)
points = pol_points(x_pix,y_pix,z_pix,map_q_grade[i],map_u_grade[i],factor)
theta = []
phi = []
for point in points:
t,p = P.vec2ang(point)
theta.append(t[0])
phi.append(p[0])
PA.projplot(theta, phi)
def plot_local_meridian(nside, ipix): theta0, phi0 = P.pix2ang(nside, ipix) theta = theta0+np.linspace(-0.1,0.1,100) phi = phi0+np.zeros(100) PA.projplot(theta,phi)