def test_eq_ne():
""" Check that equality/inequality works as expected."""
gsp = galsim.GSParams(folding_threshold=1.1e-3)
diff_gals = []
for mode in ("InclinedExponential", "InclinedSersic"):
# First test that some different initializations that should be equivalent:
same_gals = [get_prof(mode, 0.1 * galsim.radians, 3.0),
get_prof(mode, 0.1 * galsim.radians, 3.0, 0.3), # default h/r = 0.1
get_prof(mode, 0.1 * galsim.radians, 3.0, scale_height=0.3),
get_prof(mode, 0.1 * galsim.radians, 3.0, scale_h_over_r=0.1),
get_prof(mode, 0.1 * galsim.radians, 3.0, flux=1.0), # default flux=1
get_prof(mode, -0.1 * galsim.radians, 3.0), # negative i is equivalent
get_prof(mode, (np.pi - 0.1) * galsim.radians, 3.0), # also pi-theta
get_prof(mode, 18. / np.pi * galsim.degrees, 3.0),
get_prof(mode, inclination=0.1 * galsim.radians, scale_radius=3.0,
scale_height=0.3, flux=1.0),
get_prof(mode, flux=1.0, scale_radius=3.0,
scale_height=0.3, inclination=0.1 * galsim.radians),
get_prof(mode, flux=1.0, half_light_radius=3.0 * galsim.Exponential._hlr_factor,
scale_height=0.3, inclination=0.1 * galsim.radians),
get_prof(mode, flux=1.0, half_light_radius=3.0 * galsim.Exponential._hlr_factor,
scale_h_over_r=0.1, inclination=0.1 * galsim.radians)]
for gal in same_gals[1:]:
print(gal)
gsobject_compare(gal, same_gals[0])
# Set up list of galaxies we expect to all be different
diff_gals += [get_prof(mode, 0.1 * galsim.radians, 3.0, 0.3),
get_prof(mode, 0.1 * galsim.degrees, 3.0, 0.3),
get_prof(mode, 0.1 * galsim.degrees, 3.0, scale_h_over_r=0.2),
get_prof(mode, 0.1 * galsim.radians, 3.0, 3.0),
get_prof(mode, 0.2 * galsim.radians, 3.0, 0.3),
get_prof(mode, 0.1 * galsim.radians, 3.1, 0.3),
get_prof(mode, 0.1 * galsim.radians, 3.1),
get_prof(mode, 0.1 * galsim.radians, 3.0, 0.3, flux=0.5),
get_prof(mode, 0.1 * galsim.radians, 3.0, 0.3, gsparams=gsp)]
# Add some more Sersic profiles to the diff_gals list
diff_gals += [get_prof("InclinedSersic", 0.1 * galsim.radians, 3.0, 0.3, n=1.1),
get_prof("InclinedSersic", 0.1 * galsim.radians, 3.0, 0.3, trunc=4.5),
galsim.InclinedSersic(n=1.0, inclination=0.1 * galsim.radians, half_light_radius=3.0,
scale_height=0.3),
galsim.InclinedSersic(n=1.0, inclination=0.1 * galsim.radians, scale_radius=3.0,
scale_h_over_r=0.3)]
all_obj_diff(diff_gals)
def get_prof(mode, *args, **kwargs):
"""Function to get either InclinedExponential or InclinedSersic (with n=1, trunc=0)
depending on mode
"""
new_kwargs = deepcopy(kwargs)
if len(args) > 0:
new_kwargs["inclination"] = args[0]
if len(args) > 1:
new_kwargs["scale_radius"] = args[1]
if len(args) > 2:
new_kwargs["scale_height"] = args[2]
if mode == "InclinedSersic":
if not "trunc" in new_kwargs:
new_kwargs["trunc"] = 0.
if not "n" in new_kwargs:
new_kwargs["n"] = 1.
prof = galsim.InclinedSersic(**new_kwargs)
else:
if "trunc" in new_kwargs:
del new_kwargs["trunc"]
if "n" in new_kwargs:
del new_kwargs["n"]
if "flux_untruncated" in new_kwargs:
del new_kwargs["flux_untruncated"]
prof = galsim.InclinedExponential(**new_kwargs)
return prof
def make_a_galaxy(ud,wcs,affine,cosmos_cat,nfw,optics,sbparams):
"""
Method to make a single galaxy object and return stamp for
injecting into larger GalSim image
"""
# Choose a random RA, Dec around the sky_center.
# Note that for this to come out close to a square shape, we need to account for the
# cos(dec) part of the metric: ds^2 = dr^2 + r^2 d(dec)^2 + r^2 cos^2(dec) d(ra)^2
# So need to calculate dec first.
dec = sbparams.center_dec + (ud()-0.5) * sbparams.image_ysize_arcsec * galsim.arcsec
ra = sbparams.center_ra + (ud()-0.5) * sbparams.image_xsize_arcsec / numpy.cos(dec) * galsim.arcsec
world_pos = galsim.CelestialCoord(ra,dec)
# We will need the image position as well, so use the wcs to get that
image_pos = wcs.toImage(world_pos)
# We also need this in the tangent plane, which we call "world coordinates" here.
# This is still an x/y corrdinate
uv_pos = affine.toWorld(image_pos)
logger.debug('created galaxy position')
## Draw a Sersic galaxy from scratch
index = int(np.floor(ud()*len(cosmos_cat))) # This is a kludge to obain a repeatable index
gal_z = cosmos_cat[index]['ZPDF']
gal_flux = cosmos_cat[index][sbparams.bandpass]*sbparams.exp_time
inclination = cosmos_cat[index]['phi_cosmos10']*galsim.radians
scale_h_over_r = cosmos_cat[index]['q_cosmos10']
# Cosmos HLR is in units of HST pix, convert to arcsec.
# AG put a factor of q in there, unclear why?
half_light_radius=cosmos_cat[index]['hlr_cosmos10']*0.03*np.sqrt(scale_h_over_r)
n = cosmos_cat[index]['n_sersic_cosmos10']
print('galaxy index=%d z=%f flux=%f hlr=%f sersic_index=%f'%(index,gal_z,gal_flux,half_light_radius,n))
## InclinedSersic requires 0.3 < n < 6;
## set galaxy's n to another value if it falls outside this range
if n<0.3:
n=0.5
elif n>=6:
n=4
else:
pass
## Very large HLRs will also make GalSim fail
## Set to a default, ~large but physical value.
if half_light_radius > 3:
half_light_radius = 3
else:
pass
gal = galsim.InclinedSersic(n=n,
flux=gal_flux,
half_light_radius=half_light_radius,
inclination=inclination,
scale_h_over_r=scale_h_over_r
)
logger.debug('created galaxy')
## Apply a random rotation
theta = ud()*2.0*numpy.pi*galsim.radians
gal = gal.rotate(theta)
## Get the reduced shears and magnification at this point
try:
nfw_shear, mu = nfw_lensing(nfw, uv_pos, gal_z)
g1=nfw_shear.g1; g2=nfw_shear.g2
gal = gal.lens(g1, g2, mu)
except:
print("could not lens galaxy at z = %f, setting default values..." % gal_z)
g1 = 0.0; g2 = 0.0
mu = 1.0
jitter_psf = galsim.Gaussian(flux=1,fwhm=0.05)
final=galsim.Convolve([jitter_psf,gal,optics])
logger.debug("Convolved star and PSF at galaxy position")
stamp = final.drawImage(wcs=wcs.local(image_pos))
stamp.setCenter(image_pos.x,image_pos.y)
logger.debug('drew & centered galaxy!')
galaxy_truth=truth()
galaxy_truth.ra=ra.deg; galaxy_truth.dec=dec.deg
galaxy_truth.x=image_pos.x; galaxy_truth.y=image_pos.y
galaxy_truth.g1=g1; galaxy_truth.g2=g2
galaxy_truth.mu = mu; galaxy_truth.z = gal_z
galaxy_truth.flux = stamp.added_flux
galaxy_truth.n = n; galaxy_truth.hlr = half_light_radius
galaxy_truth.inclination = inclination.deg # storing in degrees for human readability
galaxy_truth.scale_h_over_r = scale_h_over_r
logger.debug('created truth values')
try:
galaxy_truth.fwhm=final.calculateFWHM()
except galsim.errors.GalSimError:
logger.debug('fwhm calculation failed')
galaxy_truth.fwhm=-9999.0
try:
galaxy_truth.mom_size=stamp.FindAdaptiveMom().moments_sigma
except galsim.errors.GalSimError:
logger.debug('sigma calculation failed')
galaxy_truth.mom_size=-9999.
logger.debug('stamp made, moving to next galaxy')
return stamp, galaxy_truth
# Characterizing observations
band = 'b' # name of filter in which galaxy is being observed
n_obs = 30 # number of observations of duration 'exp_time'
exp_time = 600 # s
sky_level = base_sky_level * exp_time # ADU / pix
gal_flux = base_gal_flux * exp_time # ADU
seed = np.random.randint(11111111, 99999999)
###
### Draw galaxy and PSF, correcting for (what I think) are inclination effects
###
gal = galsim.InclinedSersic(n=n,
flux=gal_flux,
half_light_radius=half_light_radius,
inclination=inclination,
scale_h_over_r=scale_h_over_r)
psf = galsim.Gaussian(flux=1., fwhm=psf_fwhm)
final = galsim.Convolve([gal, psf])
gal_only_stamp = gal.drawImage(scale=pixel_scale, nx=32, ny=32)
psf_stamp = psf.drawImage(scale=pixel_scale, nx=32, ny=32)
obs_stamp = final.drawImage(scale=pixel_scale, nx=32, ny=32)
## Create noisy observations
image_obslist = []
for obs in range(n_obs):
