def test_box_redshift_space_density():
"""Check that a redshift-space density field can be generated."""
# Realise Gaussian box and velocity field
np.random.seed(11)
box = CosmoBox(cosmo=default_cosmo,
box_scale=(1e2, 1e2, 1e2),
nsamp=16,
realise_now=False)
box.realise_density()
box.realise_velocity()
# Get redshift-space density field
vel_z = np.fft.ifftn(box.velocity_k[2]).real
delta_s = box.redshift_space_density(delta_x=box.delta_x,
velocity_z=vel_z,
sigma_nl=200.,
method='linear')
# Check that redshift-space density field is valid
assert delta_s.shape == (16, 16, 16)
# assert delta_s.dtype == np.float64
assert np.all(~np.isnan(delta_s))
from fastbox.box import CosmoBox, default_cosmo
from numpy import fft
# Gaussian box
np.random.seed(10)
box = CosmoBox(cosmo=default_cosmo,
box_scale=(1e2, 1e2, 1e2),
nsamp=128,
realise_now=False)
box.realise_density()
box.realise_velocity()
# Plot real-space density field
plt.matshow(box.delta_x[0], vmin=-1., vmax=20., cmap='cividis')
plt.title("Real-space")
plt.colorbar()
# Get redshift-space density field
vel_z = fft.ifftn(box.velocity_k[2]).real
delta_s = box.redshift_space_density(delta_x=box.delta_x,
velocity_z=vel_z,
sigma_nl=200.,
method='linear')
plt.matshow(delta_s[0], vmin=-1., vmax=20., cmap='cividis')
plt.title("Redshift-space")
plt.colorbar()
plt.show()
# (1b) Rescale tracer by bias [FIXME: Check this is being done in the right order]
tracer = fastbox.tracers.HITracer(box)
delta_hi = box.delta_x * tracer.bias_HI()
# (1c) Transform to a log-normal field
delta_ln = box.lognormal(delta_hi)
# (1d) Calculate radial velocity field (uses Gaussian density field; FIXME)
vel_k = box.realise_velocity(delta_x=box.delta_x, inplace=True)
vel_z = fft.ifftn(
vel_k[2]).real # inverse FFT to get real-space radial velocity
# (1e) Transform to redshift space
delta_s = box.redshift_space_density(delta_x=delta_ln.real,
velocity_z=vel_z,
sigma_nl=120.,
method='linear')
# (1f) Scale by mean brightness temperature (in mK), and include mean
signal_cube = tracer.signal_amplitude() * (1. + delta_s)
print("\t(1) Generating box complete (%3.3f sec)" % (time.time() - t0))
#-------------------------------------------------------------------------------
# Add foregrounds
#-------------------------------------------------------------------------------
print("(2) Adding foregrounds...")
t0 = time.time()
# Create new foreground model
fg = ForegroundModel(box)