def cel2gal(ra, dec, inverse=False):
_r, _d = ra * np.pi / 180., (np.pi / 2. - dec * np.pi / 180.)
if inverse:
r = hp.Rotator(coord=['G', 'C'])
else:
r = hp.Rotator(coord=['C', 'G'])
_d, _r = r(_d, _r)
return _r * 180. / np.pi, (np.pi / 2. - _d) * 180. / np.pi
def map_rotation(x, theta=22.5, phi=22.5, inv=None, PutToZero=False):
nside = gnside(x)
npix = hpy.nside2npix(nside)
pix = np.arange(npix)
t, p = hpy.pix2ang(nside, pix) #theta, phi
r = hpy.Rotator(deg=True, rot=[theta, phi], inv=inv)
map_rot = -1e10 * np.ones(npix)
trot, prot = r(t, p)
u = hpy.ang2pix(nside=nside, phi=prot, theta=trot)
map_rot[u] = x
ind = np.where(map_rot > -1e9)[0]
jnd = np.where(map_rot < -1e9)[0]
if PutToZero:
map_rot[jnd] = np.mean(map_rot)
else:
for i in jnd:
d = np.sqrt((t[ind] - t[i])**2 + (p[ind] - p[i])**2)
I = np.argsort(d)
map_rot[i] = np.mean(map_rot[ind[I[0:10]]])
return map_rot
def get_theta_phi(ra, dec):
'''Get theta, phi [radians] used in Healpy from RA, DEC [degree].'''
rot = hp.Rotator(coord=['C', 'G'])
theta_equ, phi_equ = np.deg2rad(90.-dec), np.deg2rad(ra)
theta_gal, phi_gal = rot(theta_equ, phi_equ)
return theta_gal, phi_gal
def get_nhits(nside_out=64):
""" Generates an Nhits map in Galactic coordinates.
Parameters
----------
nside_out : int
Output resolution.
Returns
-------
ndarray
Hits map.
"""
try:
# Read in a hits map that has already been calculated
# in galactic coordinates
mp_G = hp.read_map(_SO_HIT_MAP, verbose=False)
except FileNotFoundError:
# if reading in galactic map fails, read in
# celestial coordinates map and rotate it.
mp_C = hp.read_map(_SO_HIT_MAP, verbose=False)
nside_l = hp.get_nside(mp_C)
nside_h = 512
ipixG = np.arange(hp.nside2npix(nside_h))
thG, phiG = hp.pix2ang(nside_h, ipixG)
r = hp.Rotator(coord=['G', 'C'])
thC, phiC = r(thG, phiG)
ipixC = hp.ang2pix(nside_l, thC, phiC)
mp_G = hp.ud_grade(mp_C[ipixC], nside_out=nside_l)
return hp.ud_grade(mp_G, nside_out=nside_out)
def rotate(self, *a, **kw):
kw['inv'] = kw.get('inv', True)
rot = healpy.Rotator(*a, **kw)
thetas0, phis0 = self._thetas_phis
thetas, phis = rot(thetas0, phis0)
rmap = healpy.get_interp_val(self.map, thetas, phis)
return HealHist(rmap)
def change_coord(m, coord):
"""
Define the new binning.
Parameters
----------
m : array
map to be converted
coord: list
list of two strings choosen among 'G', 'C', 'E'. E.g.: to go from galactic to
celestial coordinates: coord = ['G', 'C']
Returns
-------
array
the array with the new map
"""
# Basic HEALPix parameters
npix = m.shape[-1]
nside = hp.npix2nside(npix)
ang = hp.pix2ang(nside, np.arange(npix))
# Select the coordinate transformation
rot = hp.Rotator(coord=reversed(coord))
# Convert the coordinates
new_ang = rot(*ang)
new_pix = hp.ang2pix(nside, *new_ang)
return m[..., new_pix]
