def galaxy(fstate, nside, pol, filename, spectral_index):
"""Generate a Milky way only foreground map.
Use Haslam (extrapolated with a spatially varying spectral index) as a base,
and then generate random spatial, spectral and polarisation fluctuations for
unconstrained modes.
The requested map must have more than two frequencies for this type.
"""
if fstate.frequencies.shape[0] < 2:
print("Number of frequencies must be more than two.")
return
from cora.foreground import galaxy
# Read in arguments.
gal = galaxy.ConstrainedGalaxy()
gal.nside = nside
gal.frequencies = fstate.frequencies
gal.spectral_map = spectral_index
# Fetch galactic sky
cs = gal.getpolsky() if pol == "full" else gal.getsky()
# Save map
write_map(filename, cs, gal.frequencies, fstate.freq_width, pol != "none")
def foreground(fstate, nside, pol, filename, maxflux):
"""Generate a full foreground sky map.
The requested map must have more than two frequencies for this type.
"""
if fstate.frequencies.shape[0] < 2:
print("Number of frequencies must be more than two.")
return
from cora.foreground import galaxy, pointsource
# Read in arguments.
gal = galaxy.ConstrainedGalaxy()
gal.nside = nside
gal.frequencies = fstate.frequencies
# Fetch galactic sky
cs = gal.getpolsky() if pol == "full" else gal.getsky()
# Fetch point source maps
ps = pointsource.CombinedPointSources.like_map(gal)
ps.flux_max = maxflux
cs = cs + (ps.getpolsky() if pol == "full" else ps.getsky())
# Save map
write_map(filename, cs, gal.frequencies, fstate.freq_width, pol != "none")
def gen_galaxy(nside, freq, num):
gal_map = np.zeros((num, 1, hp.nside2npix(nside)), dtype=np.float64)
gal = galaxy.ConstrainedGalaxy()
gal.nside = nside
# gal.frequencies = freq
gal.frequencies = np.array(
[freq, freq + 0.1]) # the number of frequencies must be more than two.
for i in range(num):
gal_ = gal.getsky()
gal_map[i] = gal_.mean(axis=0, keepdims=True)
return gal_map
def get_cora_polsky(self, pfrac_max=None):
from cora.foreground import galaxy
gal = galaxy.ConstrainedGalaxy()
gal.nside = self.nside
gal.frequencies = self.nu_axis * 1e-6 # MHz - self.nu_axis is in Hz.
stokes_cubes = gal.getpolsky()
I, Q, U, V = [stokes_cubes[:, i, :] for i in range(4)]
if self.unpolarized == True:
Q *= 0
U *= 0
V *= 0
return I, Q, U, V
def galaxy(ctx, spectral_index):
"""Generate a Milky way only foreground map.
Use Haslam (extrapolated with a spatially varying spectral index) as a base,
and then generate random spatial, spectral and polarisation fluctuations for
unconstrained modes.
"""
from cora.foreground import galaxy
# Read in arguments.
gal = galaxy.ConstrainedGalaxy()
gal.nside = ctx.obj.nside
gal.frequencies = ctx.obj.freq
gal.spectral_map = spectral_index
# Fetch galactic sky
cs = gal.getpolsky() if ctx.obj.full_pol else gal.getsky()
# Save map
write_map(ctx.obj.filename, cs, gal.frequencies, ctx.obj.freq_width,
ctx.obj.include_pol)
def foreground(ctx, maxflux):
"""Generate a full foreground sky map."""
from cora.foreground import galaxy, pointsource
# Read in arguments.
gal = galaxy.ConstrainedGalaxy()
gal.nside = ctx.obj.nside
gal.frequencies = ctx.obj.freq
# Fetch galactic sky
cs = gal.getpolsky() if ctx.obj.full_pol else gal.getsky()
# Fetch point source maps
ps = pointsource.CombinedPointSources.like_map(gal)
ps.flux_max = maxflux
cs = cs + (ps.getpolsky() if ctx.obj.full_pol else ps.getsky())
# Save map
write_map(ctx.obj.filename, cs, gal.frequencies, ctx.obj.freq_width,
ctx.obj.include_pol)
def test_galaxy():
cr = galaxy.ConstrainedGalaxy()
cr.nside = nside
cr.frequencies = fa
unpol = cr.getsky()
assert unpol.shape == (32, 12 * nside**2)
pol = cr.getpolsky()
assert pol.shape == (32, 4, 12 * nside**2)
# Check fluctuation amplitude for unpol
ustd = unpol.std(axis=-1)
assert (ustd > 10.0).all()
assert (ustd < 50.0).all()
# Check fluctuation amplitude for pol
pstd = pol.std(axis=-1)
assert (pstd[:, 0] > 10.0).all()
assert (pstd[:, 0] < 50.0).all()
assert (pol.std(axis=-1)[:, 1:3] > 0.1).all()
assert (pol.std(axis=-1)[:, 1:3] < 3.0).all()
assert (pol.std(axis=-1)[:, 3] == 0.0).all()