def main():
pr = cProfile.Profile()
pr.enable()
rng = galsim.UniformDeviate(8675309)
wcs = galsim.FitsWCS('../tests/des_data/DECam_00154912_12_header.fits')
image = galsim.Image(xsize, ysize, wcs=wcs)
bandpass = galsim.Bandpass('LSST_r.dat', wave_type='nm').thin(0.1)
base_wavelength = bandpass.effective_wavelength
angles = galsim.FRatioAngles(fratio, obscuration, rng)
sensor = galsim.SiliconSensor(rng=rng, nrecalc=nrecalc)
# Figure out the local_sidereal time from the observation location and time.
lsst_lat = '-30:14:23.76'
lsst_long = '-70:44:34.67'
obs_time = '2012-11-24 03:37:25.023964' # From the header of the wcs file
obs = astropy.time.Time(obs_time, scale='utc', location=(lsst_long + 'd', lsst_lat + 'd'))
local_sidereal_time = obs.sidereal_time('apparent').value
# Convert the ones we need below to galsim Angles.
local_sidereal_time *= galsim.hours
lsst_lat = galsim.Angle.from_dms(lsst_lat)
times = []
mem = []
phot = []
t0 = time.clock()
for iobj in range(nobjects):
sys.stderr.write('.')
psf = make_psf(rng)
gal = make_gal(rng)
obj = galsim.Convolve(psf, gal)
sed = get_sed(rng)
waves = galsim.WavelengthSampler(sed=sed, bandpass=bandpass, rng=rng)
image_pos = get_pos(rng)
sky_coord = wcs.toWorld(image_pos)
bounds, offset = calculate_bounds(obj, image_pos, image)
ha = local_sidereal_time - sky_coord.ra
dcr = galsim.PhotonDCR(base_wavelength=base_wavelength,
obj_coord=sky_coord, HA=ha, latitude=lsst_lat)
surface_ops = (waves, angles, dcr)
obj.drawImage(method='phot', image=image[bounds], offset=offset,
rng=rng, sensor=sensor,
surface_ops=surface_ops)
times.append(time.clock() - t0)
mem.append(resource.getrusage(resource.RUSAGE_SELF).ru_maxrss)
phot.append(obj.flux)
image.write('phot.fits')
phot = np.cumsum(phot)
make_plots(times, mem, phot)
pr.disable()
ps = pstats.Stats(pr).sort_stats('time')
ps.print_stats(20)
def test_dcr():
"""Test the dcr surface op
"""
# This tests that implementing DCR with the surface op is equivalent to using
# ChromaticAtmosphere.
# We use fairly extreme choices for the parameters to make the comparison easier, so
# we can still get good discrimination of any errors with only 10^6 photons.
zenith_angle = 45 * galsim.degrees # Larger angle has larger DCR.
parallactic_angle = 129 * galsim.degrees # Something random, not near 0 or 180
pixel_scale = 0.03 # Small pixel scale means shifts are many pixels, rather than a fraction.
alpha = -1.2 # The normal alpha is -0.2, so this is exaggerates the effect.
bandpass = galsim.Bandpass('LSST_r.dat', 'nm')
base_wavelength = bandpass.effective_wavelength
base_wavelength += 500 # This exaggerates the effects fairly substantially.
sed = galsim.SED('CWW_E_ext.sed', wave_type='ang', flux_type='flambda')
flux = 1.e6
base_PSF = galsim.Kolmogorov(fwhm=0.3)
# Use ChromaticAtmosphere
im1 = galsim.ImageD(50, 50, scale=pixel_scale)
star = galsim.DeltaFunction() * sed
star = star.withFlux(flux, bandpass=bandpass)
chrom_PSF = galsim.ChromaticAtmosphere(base_PSF,
base_wavelength=base_wavelength,
zenith_angle=zenith_angle,
parallactic_angle=parallactic_angle,
alpha=alpha)
chrom = galsim.Convolve(star, chrom_PSF)
chrom.drawImage(bandpass, image=im1)
# Use PhotonDCR
im2 = galsim.ImageD(50, 50, scale=pixel_scale)
dcr = galsim.PhotonDCR(base_wavelength=base_wavelength,
zenith_angle=zenith_angle,
parallactic_angle=parallactic_angle,
alpha=alpha)
achrom = base_PSF.withFlux(flux)
rng = galsim.BaseDeviate(31415)
wave_sampler = galsim.WavelengthSampler(sed, bandpass, rng)
surface_ops = [wave_sampler, dcr]
achrom.drawImage(image=im2,
method='phot',
rng=rng,
surface_ops=surface_ops)
im1 /= flux # Divide by flux, so comparison is on a relative basis.
im2 /= flux
printval(im2, im1, show=False)
np.testing.assert_almost_equal(
im2.array,
im1.array,
decimal=4,
err_msg="PhotonDCR didn't match ChromaticAtmosphere")
# Repeat with thinned bandpass and SED to check that thin still works well.
im3 = galsim.ImageD(50, 50, scale=pixel_scale)
thin = 0.1 # Even higher also works. But this is probably enough.
thin_bandpass = bandpass.thin(thin)
thin_sed = sed.thin(thin)
print('len bp = %d => %d' %
(len(bandpass.wave_list), len(thin_bandpass.wave_list)))
print('len sed = %d => %d' % (len(sed.wave_list), len(thin_sed.wave_list)))
wave_sampler = galsim.WavelengthSampler(thin_sed, thin_bandpass, rng)
achrom.drawImage(image=im3,
method='phot',
rng=rng,
surface_ops=surface_ops)
im3 /= flux
printval(im3, im1, show=False)
np.testing.assert_almost_equal(
im3.array,
im1.array,
decimal=4,
err_msg="thinning factor %f led to 1.e-4 level inaccuracy" % thin)
# Check scale_unit
im4 = galsim.ImageD(50, 50, scale=pixel_scale / 60)
dcr = galsim.PhotonDCR(base_wavelength=base_wavelength,
zenith_angle=zenith_angle,
parallactic_angle=parallactic_angle,
scale_unit='arcmin',
alpha=alpha)
surface_ops = [wave_sampler, dcr]
achrom.dilate(1. / 60).drawImage(image=im4,
method='phot',
rng=rng,
surface_ops=surface_ops)
im4 /= flux
printval(im4, im1, show=False)
np.testing.assert_almost_equal(
im4.array,
im1.array,
decimal=4,
err_msg="PhotonDCR with scale_unit=arcmin, didn't match")
# Check some other valid options
# alpha = 0 means don't do any size scaling.
# obj_coord, HA and latitude are another option for setting the angles
# pressure, temp, and water pressure are settable.
# Also use a non-trivial WCS.
wcs = galsim.FitsWCS('des_data/DECam_00154912_12_header.fits')
image = galsim.Image(50, 50, wcs=wcs)
bandpass = galsim.Bandpass('LSST_r.dat', wave_type='nm').thin(0.1)
base_wavelength = bandpass.effective_wavelength
lsst_lat = galsim.Angle.from_dms('-30:14:23.76')
lsst_long = galsim.Angle.from_dms('-70:44:34.67')
local_sidereal_time = 3.14 * galsim.hours # Not pi. This is the time for this observation.
im5 = galsim.ImageD(50, 50, wcs=wcs)
obj_coord = wcs.toWorld(im5.true_center)
base_PSF = galsim.Kolmogorov(fwhm=0.9)
achrom = base_PSF.withFlux(flux)
dcr = galsim.PhotonDCR(
base_wavelength=bandpass.effective_wavelength,
obj_coord=obj_coord,
HA=local_sidereal_time - obj_coord.ra,
latitude=lsst_lat,
pressure=72, # default is 69.328
temperature=290, # default is 293.15
H2O_pressure=0.9) # default is 1.067
#alpha=0) # default is 0, so don't need to set it.
surface_ops = [wave_sampler, dcr]
achrom.drawImage(image=im5,
method='phot',
rng=rng,
surface_ops=surface_ops)
im6 = galsim.ImageD(50, 50, wcs=wcs)
star = galsim.DeltaFunction() * sed
star = star.withFlux(flux, bandpass=bandpass)
chrom_PSF = galsim.ChromaticAtmosphere(
base_PSF,
base_wavelength=bandpass.effective_wavelength,
obj_coord=obj_coord,
HA=local_sidereal_time - obj_coord.ra,
latitude=lsst_lat,
pressure=72,
temperature=290,
H2O_pressure=0.9,
alpha=0)
chrom = galsim.Convolve(star, chrom_PSF)
chrom.drawImage(bandpass, image=im6)
im5 /= flux # Divide by flux, so comparison is on a relative basis.
im6 /= flux
printval(im5, im6, show=False)
np.testing.assert_almost_equal(
im5.array,
im6.array,
decimal=3,
err_msg="PhotonDCR with alpha=0 didn't match")
# Also check invalid parameters
zenith_coord = galsim.CelestialCoord(13.54 * galsim.hours, lsst_lat)
assert_raises(
TypeError,
galsim.PhotonDCR,
zenith_angle=zenith_angle,
parallactic_angle=parallactic_angle) # base_wavelength is required
assert_raises(TypeError,
galsim.PhotonDCR,
base_wavelength=500,
parallactic_angle=parallactic_angle
) # zenith_angle (somehow) is required
assert_raises(
TypeError,
galsim.PhotonDCR,
500,
zenith_angle=34.4,
parallactic_angle=parallactic_angle) # zenith_angle must be Angle
assert_raises(TypeError,
galsim.PhotonDCR,
500,
zenith_angle=zenith_angle,
parallactic_angle=34.5) # parallactic_angle must be Angle
assert_raises(TypeError,
galsim.PhotonDCR,
500,
obj_coord=obj_coord,
latitude=lsst_lat) # Missing HA
assert_raises(TypeError,
galsim.PhotonDCR,
500,
obj_coord=obj_coord,
HA=local_sidereal_time - obj_coord.ra) # Missing latitude
assert_raises(TypeError, galsim.PhotonDCR, 500,
obj_coord=obj_coord) # Need either zenith_coord, or (HA,lat)
assert_raises(TypeError,
galsim.PhotonDCR,
500,
obj_coord=obj_coord,
zenith_coord=zenith_coord,
HA=local_sidereal_time -
obj_coord.ra) # Can't have both HA and zenith_coord
assert_raises(TypeError,
galsim.PhotonDCR,
500,
obj_coord=obj_coord,
zenith_coord=zenith_coord,
latitude=lsst_lat) # Can't have both lat and zenith_coord
assert_raises(TypeError,
galsim.PhotonDCR,
500,
zenith_angle=zenith_angle,
parallactic_angle=parallactic_angle,
H20_pressure=1.) # invalid (misspelled)
assert_raises(ValueError,
galsim.PhotonDCR,
500,
zenith_angle=zenith_angle,
parallactic_angle=parallactic_angle,
scale_unit='inches') # invalid scale_unit
# Invalid to use dcr without some way of setting wavelengths.
assert_raises(galsim.GalSimError,
achrom.drawImage,
im2,
method='phot',
surface_ops=[dcr])
def test_dcr_moments():
"""Check that DCR gets the direction of the moment changes correct for some simple geometries.
i.e. Basically check the sign conventions used in the DCR code.
"""
# First, the basics.
# 1. DCR shifts blue photons closer to zenith, because the index of refraction larger.
# cf. http://lsstdesc.github.io/chroma/
# 2. Galsim models profiles as seen from Earth with North up (and therefore East left).
# 3. Hour angle is negative when the object is in the east (soon after rising, say),
# zero when crossing the zenith meridian, and then positive to the west.
# Use g-band, where the effect is more dramatic across the band than in redder bands.
# Also use a reference wavelength significantly to the red, so there should be a net
# overall shift towards zenith as well as a shear along the line to zenith.
bandpass = galsim.Bandpass('LSST_g.dat', 'nm').thin(0.1)
base_wavelength = 600 # > red end of g band
# Uniform across the band is fine for this.
sed = galsim.SED('1', wave_type='nm', flux_type='fphotons')
rng = galsim.BaseDeviate(31415)
wave_sampler = galsim.WavelengthSampler(sed, bandpass, rng)
star = galsim.Kolmogorov(fwhm=0.3,
flux=1.e6) # 10^6 photons should be enough.
im = galsim.ImageD(
50, 50, scale=0.05) # Small pixel scale, so shift is many pixels.
ra = 0 * galsim.degrees # Completely irrelevant here.
lat = -20 * galsim.degrees # Also doesn't really matter much.
# 1. HA < 0, Dec < lat Spot should be shifted up and right. e2 > 0.
dcr = galsim.PhotonDCR(base_wavelength=base_wavelength,
HA=-2 * galsim.hours,
latitude=lat,
obj_coord=galsim.CelestialCoord(
ra, lat - 20 * galsim.degrees))
surface_ops = [wave_sampler, dcr]
star.drawImage(image=im, method='phot', rng=rng, surface_ops=surface_ops)
moments = galsim.utilities.unweighted_moments(im, origin=im.true_center)
print('1. HA < 0, Dec < lat: ', moments)
assert moments['My'] > 0 # up
assert moments['Mx'] > 0 # right
assert moments['Mxy'] > 0 # e2 > 0
# 2. HA = 0, Dec < lat Spot should be shifted up. e1 < 0, e2 ~= 0.
dcr = galsim.PhotonDCR(base_wavelength=base_wavelength,
HA=0 * galsim.hours,
latitude=lat,
obj_coord=galsim.CelestialCoord(
ra, lat - 20 * galsim.degrees))
surface_ops = [wave_sampler, dcr]
star.drawImage(image=im, method='phot', rng=rng, surface_ops=surface_ops)
moments = galsim.utilities.unweighted_moments(im, origin=im.true_center)
print('2. HA = 0, Dec < lat: ', moments)
assert moments['My'] > 0 # up
assert abs(moments['Mx']) < 0.05 # not left or right
assert moments['Mxx'] < moments['Myy'] # e1 < 0
assert abs(moments['Mxy']) < 0.1 # e2 ~= 0
# 3. HA > 0, Dec < lat Spot should be shifted up and left. e2 < 0.
dcr = galsim.PhotonDCR(base_wavelength=base_wavelength,
HA=2 * galsim.hours,
latitude=lat,
obj_coord=galsim.CelestialCoord(
ra, lat - 20 * galsim.degrees))
surface_ops = [wave_sampler, dcr]
star.drawImage(image=im, method='phot', rng=rng, surface_ops=surface_ops)
moments = galsim.utilities.unweighted_moments(im, origin=im.true_center)
print('3. HA > 0, Dec < lat: ', moments)
assert moments['My'] > 0 # up
assert moments['Mx'] < 0 # left
assert moments['Mxy'] < 0 # e2 < 0
# 4. HA < 0, Dec = lat Spot should be shifted right. e1 > 0, e2 ~= 0.
dcr = galsim.PhotonDCR(base_wavelength=base_wavelength,
HA=-2 * galsim.hours,
latitude=lat,
obj_coord=galsim.CelestialCoord(ra, lat))
surface_ops = [wave_sampler, dcr]
star.drawImage(image=im, method='phot', rng=rng, surface_ops=surface_ops)
moments = galsim.utilities.unweighted_moments(im, origin=im.true_center)
print('4. HA < 0, Dec = lat: ', moments)
assert abs(moments['My']
) < 1. # not up or down (Actually slightly down in the south.)
assert moments['Mx'] > 0 # right
assert moments['Mxx'] > moments['Myy'] # e1 > 0
assert abs(
moments['Mxy']
) < 2. # e2 ~= 0 (Actually slightly negative because of curvature.)
# 5. HA = 0, Dec = lat Spot should not be shifted. e1 ~= 0, e2 ~= 0.
dcr = galsim.PhotonDCR(base_wavelength=base_wavelength,
HA=0 * galsim.hours,
latitude=lat,
obj_coord=galsim.CelestialCoord(ra, lat))
surface_ops = [wave_sampler, dcr]
star.drawImage(image=im, method='phot', rng=rng, surface_ops=surface_ops)
moments = galsim.utilities.unweighted_moments(im, origin=im.true_center)
print('5. HA = 0, Dec = lat: ', moments)
assert abs(moments['My']) < 0.05 # not up or down
assert abs(moments['Mx']) < 0.05 # not left or right
assert abs(moments['Mxx'] - moments['Myy']) < 0.1 # e1 ~= 0
assert abs(moments['Mxy']) < 0.1 # e2 ~= 0
# 6. HA > 0, Dec = lat Spot should be shifted left. e1 > 0, e2 ~= 0.
dcr = galsim.PhotonDCR(base_wavelength=base_wavelength,
HA=2 * galsim.hours,
latitude=lat,
obj_coord=galsim.CelestialCoord(ra, lat))
surface_ops = [wave_sampler, dcr]
star.drawImage(image=im, method='phot', rng=rng, surface_ops=surface_ops)
moments = galsim.utilities.unweighted_moments(im, origin=im.true_center)
print('6. HA > 0, Dec = lat: ', moments)
assert abs(moments['My']
) < 1. # not up or down (Actually slightly down in the south.)
assert moments['Mx'] < 0 # left
assert moments['Mxx'] > moments['Myy'] # e1 > 0
assert abs(
moments['Mxy']
) < 2. # e2 ~= 0 (Actually slgihtly positive because of curvature.)
# 7. HA < 0, Dec > lat Spot should be shifted down and right. e2 < 0.
dcr = galsim.PhotonDCR(base_wavelength=base_wavelength,
HA=-2 * galsim.hours,
latitude=lat,
obj_coord=galsim.CelestialCoord(
ra, lat + 20 * galsim.degrees))
surface_ops = [wave_sampler, dcr]
star.drawImage(image=im, method='phot', rng=rng, surface_ops=surface_ops)
moments = galsim.utilities.unweighted_moments(im, origin=im.true_center)
print('7. HA < 0, Dec > lat: ', moments)
assert moments['My'] < 0 # down
assert moments['Mx'] > 0 # right
assert moments['Mxy'] < 0 # e2 < 0
# 8. HA = 0, Dec > lat Spot should be shifted down. e1 < 0, e2 ~= 0.
dcr = galsim.PhotonDCR(base_wavelength=base_wavelength,
HA=0 * galsim.hours,
latitude=lat,
obj_coord=galsim.CelestialCoord(
ra, lat + 20 * galsim.degrees))
surface_ops = [wave_sampler, dcr]
star.drawImage(image=im, method='phot', rng=rng, surface_ops=surface_ops)
moments = galsim.utilities.unweighted_moments(im, origin=im.true_center)
print('8. HA = 0, Dec > lat: ', moments)
assert moments['My'] < 0 # down
assert abs(moments['Mx']) < 0.05 # not left or right
assert moments['Mxx'] < moments['Myy'] # e1 < 0
assert abs(moments['Mxy']) < 0.1 # e2 ~= 0
# 9. HA > 0, Dec > lat Spot should be shifted down and left. e2 > 0.
dcr = galsim.PhotonDCR(base_wavelength=base_wavelength,
HA=2 * galsim.hours,
latitude=lat,
obj_coord=galsim.CelestialCoord(
ra, lat + 20 * galsim.degrees))
surface_ops = [wave_sampler, dcr]
star.drawImage(image=im, method='phot', rng=rng, surface_ops=surface_ops)
moments = galsim.utilities.unweighted_moments(im, origin=im.true_center)
print('9. HA > 0, Dec > lat: ', moments)
assert moments['My'] < 0 # down
assert moments['Mx'] < 0 # left
assert moments['Mxy'] > 0 # e2 > 0
def drawObject(self, gsObject):
"""
Draw an astronomical object on all of the relevant FITS files.
@param [in] gsObject is an instantiation of the GalSimCelestialObject
class carrying all of the information for the object whose image
is to be drawn
@param [out] outputString is a string denoting which detectors the astronomical
object illumines, suitable for output in the GalSim InstanceCatalog
"""
# find the detectors which the astronomical object illumines
outputString, \
detectorList, \
centeredObj = self.findAllDetectors(gsObject)
# Make sure this object is marked as "drawn" since we only
# care that this method has been called for this object.
self.drawn_objects.add(gsObject.uniqueId)
# Compute the realized object fluxes (as drawn from the
# corresponding Poisson distribution) for each band and return
# right away if all values are zero in order to save compute.
fluxes = [gsObject.flux(bandpassName) for bandpassName in self.bandpassDict]
realized_fluxes = [galsim.PoissonDeviate(self._rng, mean=f)() for f in fluxes]
if all([f == 0 for f in realized_fluxes]):
return outputString
if len(detectorList) == 0:
# there is nothing to draw
return outputString
self._addNoiseAndBackground(detectorList)
# Create a surface operation to sample incident angles and a
# galsim.SED object for sampling the wavelengths of the
# incident photons.
fratio = 1.234 # From https://www.lsst.org/scientists/keynumbers
obscuration = 0.606 # (8.4**2 - 6.68**2)**0.5 / 8.4
angles = galsim.FRatioAngles(fratio, obscuration, self._rng)
sed_lut = galsim.LookupTable(x=gsObject.sed.wavelen,
f=gsObject.sed.flambda)
gs_sed = galsim.SED(sed_lut, wave_type='nm', flux_type='flambda',
redshift=0.)
local_hour_angle \
= self.getHourAngle(self.obs_metadata.mjd.TAI,
self.obs_metadata.pointingRA)*galsim.degrees
obs_latitude = self.observatory.getLatitude().asDegrees()*galsim.degrees
ra_obs, dec_obs = observedFromPupilCoords(gsObject.xPupilRadians,
gsObject.yPupilRadians,
obs_metadata=self.obs_metadata)
obj_coord = galsim.CelestialCoord(ra_obs*galsim.degrees,
dec_obs*galsim.degrees)
for bandpassName, realized_flux in zip(self.bandpassDict, realized_fluxes):
gs_bandpass = self.gs_bandpass_dict[bandpassName]
waves = galsim.WavelengthSampler(sed=gs_sed, bandpass=gs_bandpass,
rng=self._rng)
dcr = galsim.PhotonDCR(base_wavelength=gs_bandpass.effective_wavelength,
HA=local_hour_angle,
latitude=obs_latitude,
obj_coord=obj_coord)
# Set the object flux to the value realized from the
# Poisson distribution.
obj = centeredObj.withFlux(realized_flux)
for detector in detectorList:
name = self._getFileName(detector=detector,
bandpassName=bandpassName)
xPix, yPix = detector.camera_wrapper\
.pixelCoordsFromPupilCoords(gsObject.xPupilRadians,
gsObject.yPupilRadians,
chipName=detector.name,
obs_metadata=self.obs_metadata)
# Ensure the rng used by the sensor object is set to the desired state.
self.sensor[detector.name].rng.reset(self._rng)
surface_ops = [waves, dcr, angles]
# Desired position to draw the object.
image_pos = galsim.PositionD(xPix, yPix)
# Find a postage stamp region to draw onto. Use (sky
# noise)/3. as the nominal minimum surface brightness
# for rendering an extended object.
keep_sb_level = np.sqrt(self.sky_bg_per_pixel)/3.
bounds = self.getStampBounds(gsObject, realized_flux, image_pos,
keep_sb_level, 3*keep_sb_level)
# Ensure the bounds of the postage stamp lie within the image.
bounds = bounds & self.detectorImages[name].bounds
if bounds.isDefined():
# offset is relative to the "true" center of the postage stamp.
offset = image_pos - bounds.true_center
obj.drawImage(method='phot',
offset=offset,
rng=self._rng,
maxN=int(1e6),
image=self.detectorImages[name][bounds],
sensor=self.sensor[detector.name],
surface_ops=surface_ops,
add_to_image=True,
poisson_flux=False,
gain=detector.photParams.gain)
# If we are writing centroid files,store the entry.
if self.centroid_base_name is not None:
centroid_tuple = (detector.fileName, bandpassName, gsObject.uniqueId,
gsObject.flux(bandpassName), xPix, yPix)
self.centroid_list.append(centroid_tuple)
self.write_checkpoint()
return outputString
