def test_bug_276(make_data_path):
ui.load_pha(make_data_path('3c273.pi'))
ui.set_model('polynom1d.p1')
ui.fit()
ui.covar()
scal = ui.get_covar_results().parmaxes
ui.sample_flux(ui.get_model_component('p1'), 0.5, 1, num=5, correlated=False, scales=scal)
def test_background():
tmpdir = tempfile.mkdtemp()
curdir = os.getcwd()
os.chdir(tmpdir)
kT_sim = 1.0
Z_sim = 0.0
norm_sim = 4.0e-2
nH_sim = 0.04
redshift = 0.01
exp_time = (200., "ks")
area = (1000., "cm**2")
wcs = create_dummy_wcs()
abs_model = WabsModel(nH_sim)
events = EventList.create_empty_list(exp_time, area, wcs)
spec_model = TableApecModel(0.05, 12.0, 5000, thermal_broad=False)
spec = spec_model.return_spectrum(kT_sim, Z_sim, redshift, norm_sim)
new_events = events.add_background(spec_model.ebins, spec, prng=prng,
absorb_model=abs_model)
new_events = ACIS_I(new_events, rebin=False, convolve_psf=False, prng=prng)
new_events.write_spectrum("background_evt.pi", clobber=True)
os.system("cp %s ." % new_events.parameters["ARF"])
os.system("cp %s ." % new_events.parameters["RMF"])
load_user_model(mymodel, "wapec")
add_user_pars("wapec", ["nH", "kT", "metallicity", "redshift", "norm"],
[0.01, 4.0, 0.2, redshift, norm_sim*0.8],
parmins=[0.0, 0.1, 0.0, -20.0, 0.0],
parmaxs=[10.0, 20.0, 10.0, 20.0, 1.0e9],
parfrozen=[False, False, False, True, False])
load_pha("background_evt.pi")
set_stat("cstat")
set_method("simplex")
ignore(":0.5, 8.0:")
set_model("wapec")
fit()
set_covar_opt("sigma", 1.6)
covar()
res = get_covar_results()
assert np.abs(res.parvals[0]-nH_sim) < res.parmaxes[0]
assert np.abs(res.parvals[1]-kT_sim) < res.parmaxes[1]
assert np.abs(res.parvals[2]-Z_sim) < res.parmaxes[2]
assert np.abs(res.parvals[3]-norm_sim) < res.parmaxes[3]
os.chdir(curdir)
shutil.rmtree(tmpdir)
def test_bug_276(make_data_path):
ui.load_pha(make_data_path('3c273.pi'))
ui.set_model('polynom1d.p1')
ui.fit()
ui.covar()
scal = ui.get_covar_results().parmaxes
ui.sample_flux(ui.get_model_component('p1'),
0.5,
1,
num=5,
correlated=False,
scales=scal)
def fit(self, do_covar=False, do_conf=False):
"""Perform fit using profile likelihood technique for background estimation and subtraction."""
listnames = self.get_noticed_list() # [ids.name for ids in self.listids[self.noticed_ids]]
if len(listnames) > 0:
wfit(listnames)
print_fit()
if do_covar is True:
sau.covar(*listnames)
if do_conf is True:
sau.set_conf_opt('max_rstat', 10000)
sau.conf(*listnames)
print_conf()
else:
print("Empty noticed runs list. No fit")
def run_hspec_fit(self, model, thres_low, thres_high):
"""Run the gammapy.hspec fit
Parameters
----------
model : str
Sherpa model
thres_high : `~gammapy.spectrum.Energy`
Upper threshold of the spectral fit
thres_low : `~gammapy.spectrum.Energy`
Lower threshold of the spectral fit
"""
log.info("Starting HSPEC")
import sherpa.astro.ui as sau
from ..hspec import wstat
from sherpa.models import PowLaw1D
if model == 'PL':
p1 = PowLaw1D('p1')
p1.gamma = 2.2
p1.ref = 1e9
p1.ampl = 6e-19
else:
raise ValueError('Desired Model is not defined')
thres = thres_low.to('keV').value
emax = thres_high.to('keV').value
sau.freeze(p1.ref)
sau.set_conf_opt("max_rstat", 100)
list_data = []
for obs in self.observations:
datid = obs.phafile.parts[-1][7:12]
sau.load_data(datid, str(obs.phafile))
sau.notice_id(datid, thres, emax)
sau.set_source(datid, p1)
list_data.append(datid)
wstat.wfit(list_data)
sau.covar()
fit_val = sau.get_covar_results()
fit_attrs = ('parnames', 'parvals', 'parmins', 'parmaxes')
fit = dict((attr, getattr(fit_val, attr)) for attr in fit_attrs)
fit = self.apply_containment(fit)
sau.clean()
self.fit = fit
def get_fluxes(ids, z, fluxes, fitstats, nsims=10):
shp.covar()
dataScale = shp.get_covar_results().parmaxes
if fitstats.rstat <= 3.0:
if all(d is None for d in dataScale):
fx = _calc_fluxes(ids, z=z, nsims=nsims)
fluxes["fx"], fluxes["fx_obs"], fluxes["fx_int"] = fx[:, 0]
else:
fx = _calc_fluxes(ids, z=z, dataScale=dataScale, nsims=nsims)
fluxes["fx"], fluxes["fx_ErrMin"], fluxes["fx_ErrMax"] = fx[0, :]
fluxes["fx_obs"], fluxes["fx_obs_ErrMin"], fluxes[
"fx_obs_ErrMax"] = fx[1, :]
fluxes["fx_int"], fluxes["fx_int_ErrMin"], fluxes[
"fx_int_ErrMax"] = fx[2, :]
else:
fx = _calc_fluxes(ids, z=z, nsims=nsims)
fluxes["fx"], fluxes["fx_obs"], fluxes["fx_int"] = fx[:, 0]
return fluxes
def plaw_fit(alpha_sim):
tmpdir = tempfile.mkdtemp()
curdir = os.getcwd()
os.chdir(tmpdir)
nH_sim = 0.02
norm_sim = 1.0e-4
redshift = 0.01
exp_time = 5.0e4
area = 40000.0
inst_name = "hdxi"
spec = Spectrum.from_powerlaw(alpha_sim, redshift, norm_sim)
spec.apply_foreground_absorption(nH_sim)
e = spec.generate_energies(exp_time, area)
pt_src = PointSourceModel(30.0, 45.0, e.size)
write_photon_list("plaw_model",
"plaw_model",
e.flux,
pt_src.ra,
pt_src.dec,
e,
clobber=True)
instrument_simulator("plaw_model_simput.fits",
"plaw_model_evt.fits",
exp_time,
inst_name, [30.0, 45.0],
astro_bkgnd=None,
instr_bkgnd_scale=0.0)
inst = get_instrument_from_registry(inst_name)
arf = AuxiliaryResponseFile(inst["arf"])
rmf = RedistributionMatrixFile(inst["rmf"])
os.system("cp %s ." % arf.filename)
os.system("cp %s ." % rmf.filename)
write_spectrum("plaw_model_evt.fits", "plaw_model_evt.pha", clobber=True)
load_user_model(mymodel, "wplaw")
add_user_pars("wplaw", ["nH", "norm", "redshift", "alpha"],
[0.01, norm_sim * 0.8, redshift, 0.9],
parmins=[0.0, 0.0, 0.0, 0.1],
parmaxs=[10.0, 1.0e9, 10.0, 10.0],
parfrozen=[False, False, True, False])
load_pha("plaw_model_evt.pha")
set_stat("cstat")
set_method("simplex")
ignore(":0.5, 9.0:")
set_model("wplaw")
fit()
set_covar_opt("sigma", 1.645)
covar()
res = get_covar_results()
assert np.abs(res.parvals[0] - nH_sim) < res.parmaxes[0]
assert np.abs(res.parvals[1] - norm_sim) < res.parmaxes[1]
assert np.abs(res.parvals[2] - alpha_sim) < res.parmaxes[2]
os.chdir(curdir)
shutil.rmtree(tmpdir)
def fit_sherpa(obsid_list, redshift, nH_Gal, energy, min_counts=25, kT_guess=3, Ab_guess=1, fix_nH_Gal=True, fix_abund=False, find_errors=True):
spectra = []
for obs in obsid_list:
temp = glob.glob('xaf_*_' + obs + '.pi') # get spectra of regions
spectra.append(temp) # spectra will be made of lists which have xaf_*_obs.pi filenames - access with spectra[i][j]
spectra.sort()
num_obs = len(obsid_list)
num_reg = len(temp)
filename = 'spectra_wabs_mekal.dat'
results_file = open(filename, "w")
results_file.write('# Fit results for wabs*mekal (zeros indicate that no fitting was performed)\n')
results_file.write('# Reg_no. kT kT_loerr kT_hierr Z Z_loerr Z_hierr norm norm_loerr norm_hierr nH_Gal nH_loerr nH_hierr red_chisq total_counts num_bins\n')
for i in range(num_reg):
sherpa.clean() # clean everything
cnts = numpy.zeros(num_obs) # make array of zeros with index length same as num_obs to store counts
max_rate = numpy.zeros(num_obs) # max count rate [counts/s/keV]
data_set = 0 # data set number
good_src_ids = numpy.zeros(num_obs, dtype=int) - 1
for j in range(num_obs):
sherpa.load_pha(data_set, spectra[j][i]) # load xaf_#_obs_####.pi and .arf and .rmf files.
sherpa.ignore_id(data_set, 0.0, energy[0])
sherpa.ignore_id(data_set, energy[1], None)
cnts[j] = sherpa.calc_data_sum(energy[0], energy[1], data_set)
cnt_rate = sherpa.get_rate(data_set, filter=True)
if len(cnt_rate) == 0:
max_rate[j] = 0.0 # when few counts (<50), get_rate can return zero-length array
else:
max_rate[j] = numpy.max(cnt_rate)
sherpa.subtract(data_set) # subtract background
sherpa.set_source(data_set, sherpa.xswabs.abs1 * sherpa.xsmekal.plsm1) # 1 temperature mekal model fit
good_src_ids[j] = data_set
data_set += 1 # same run for region but different obs
# Filter out ignored obs
good_src_ids_indx = numpy.where(good_src_ids >= 0)
good_src_ids = good_src_ids[good_src_ids_indx]
max_rate = max_rate[good_src_ids_indx]
cnts = cnts[good_src_ids_indx]
totcnts = numpy.sum(cnts)
if totcnts >= min_counts:
print('Fitting spectra in region: ' + str(i))
abs1.nH = nH_Gal
abs1.cache = 0
if fix_nH_Gal:
sherpa.freeze(abs1.nH)
else:
sherpa.thaw(abs1.nH)
plsm1.kt = kT_guess
sherpa.thaw(plsm1.kt)
plsm1.Abundanc = Ab_guess
if fix_abund:
sherpa.freeze(plsm1.Abundanc)
else:
sherpa.thaw(plsm1.Abundanc)
plsm1.redshift = redshift
sherpa.freeze(plsm1.redshift)
plsm1.cache = 0
sherpa.fit()
fit_result = sherpa.get_fit_results()
red_chi2 = fit_result.rstat
num_bins = fit_result.numpoints
if fix_nH_Gal:
nH = nH_Gal
kT = fit_result.parvals[0]
if fix_abund:
Z = Ab_guess
norm = fit_result.parvals[1]
else:
Z = fit_result.parvals[1]
norm = fit_result.parvals[2]
else:
nH = fit_result.parvals[0]
kT = fit_result.parvals[1]
if fix_abund:
Z = Ab_guess
norm = fit_result.parvals[2]
else:
Z = fit_result.parvals[2]
norm = fit_result.parvals[3]
del fit_result
if find_errors:
sherpa.covar()
covar_result = sherpa.get_covar_results()
if fix_nH_Gal:
nH_loerr = 0.0
nH_hierr = 0.0
kT_loerr = covar_result.parmins[0]
kT_hierr = covar_result.parmaxes[0]
if fix_abund:
Z_loerr = 0.0
Z_hierr = 0.0
norm_loerr = covar_result.parmins[1]
norm_hierr = covar_result.parmaxes[1]
else:
Z_loerr = covar_result.parmins[1]
Z_hierr = covar_result.parmaxes[1]
norm_loerr = covar_result.parmins[2]
norm_hierr = covar_result.parmaxes[2]
else:
nH_loerr = covar_result.parmins[0]
nH_hierr = covar_result.parmaxes[0]
kT_loerr = covar_result.parmins[1]
kT_hierr = covar_result.parmaxes[1]
if fix_abund:
Z_loerr = 0.0
Z_hierr = 0.0
norm_loerr = covar_result.parmins[2]
norm_hierr = covar_result.parmaxes[2]
else:
Z_loerr = covar_result.parmins[2]
Z_hierr = covar_result.parmaxes[2]
norm_loerr = covar_result.parmins[3]
norm_hierr = covar_result.parmaxes[3]
del covar_result
# Check for failed errors (= None) and set them to +/- best-fit value
if not fix_nH_Gal:
if nH_loerr is None: nH_loerr = -nH # is was ==
if nH_hierr is None: nH_hierr = nH
if kT_loerr is None: kT_loerr = -kT
if kT_hierr is None: kT_hierr = kT
if not fix_abund:
if Z_loerr is None: Z_loerr = -Z
if Z_hierr is None: Z_hierr = Z
if norm_loerr is None: norm_loerr = -norm
if norm_hierr is None: norm_hierr = norm
else:
kT_loerr = 0.0
Z_loerr = 0.0
nH_loerr = 0.0
norm_loerr = 0.0
kT_hierr = 0.0
Z_hierr = 0.0
nH_hierr = 0.0
norm_hierr = 0.0
else: # if total counts < min_counts, just write zeros
print('\n Warning: no fit performed for for region: ' + str(i))
print('\n Spectra have insufficient counts after filtering or do not exist.')
print('\n --> All parameters for this region set to 0.0.')
kT = 0.0
Z = 0.0
nH = 0.0
norm = 0.0
kT_loerr = 0.0
Z_loerr = 0.0
nH_loerr = 0.0
norm_loerr = 0.0
kT_hierr = 0.0
Z_hierr = 0.0
nH_hierr = 0.0
norm_hierr = 0.0
red_chi2 = 0.0
num_bins = 0
reg_id = spectra[0][i].split('_') # Splits string after every underscore so that region number can be accessed. reg_id[1] is accessed because that is the region number after 'xaf'
results_file.write('%7r %7.4f %7.4f %7.4f %7.4f %7.4f %7.4f %6.4e %6.4e %6.4e %7.4f %7.4f %7.4f %7.4f %8.1f %8r\n' % (int(reg_id[1]), kT, kT_loerr, kT_hierr, Z, Z_loerr, Z_hierr, norm, norm_loerr, norm_hierr, nH, nH_loerr, nH_hierr, red_chi2, totcnts, num_bins)) # Write all data to a file
results_file.close()
filename = 'skymap_ex.fits'
nomposstr = '05h34m31.94s 22d00m52.2s'
header = fits.getheader(filename)
proj = wcs.Projection(header)
xc, yc = float(header['NAXIS1']) / 2., float(header['NAXIS2']) / 2.
ui.load_image(filename)
ui.notice2d('circle({0}, {1}, {2})'.format(xc, yc, float(header['NAXIS2']) / 4.))
ui.set_source(ui.gauss2d.g1 + ui.gauss2d.g2)
g1.xpos = xc
g1.ypos = yc
g2.fwhm = g1.fwhm = 3.
ui.link(g2.xpos, g1.xpos)
ui.link(g2.ypos, g1.ypos)
g2.ampl = 50.
g1.ampl = 50.
ui.guess()
ui.fit()
ui.image_fit()
ui.covar()
conf = ui.get_covar_results()
conf_dict = dict([(n,(v, l, h)) for n,v,l,h in
zip(conf.parnames, conf.parvals, conf.parmins, conf.parmaxes)])
x, y = proj.toworld((conf_dict['g1.xpos'][0], conf_dict['g1.ypos'][0]))
xmin, ymin = proj.toworld((conf_dict['g1.xpos'][0] + conf_dict['g1.xpos'][1],
conf_dict['g1.ypos'][0] + conf_dict['g1.ypos'][1]))
xmax, ymax = proj.toworld((conf_dict['g1.xpos'][0] + conf_dict['g1.xpos'][2],
conf_dict['g1.ypos'][0] + conf_dict['g1.ypos'][2]))
nompos = positions.str2pos(nomposstr, proj)
print('{0} ({1}-{2}) vs {3}'.format(x, xmin, xmax, nompos[0][0][0]))
print('{0} ({1}-{2}) vs {3}'.format(y, ymin, ymax, nompos[0][0][1]))
def do_beta_model(source, v_field, em_field):
tmpdir = tempfile.mkdtemp()
curdir = os.getcwd()
os.chdir(tmpdir)
ds = source.ds
A = 3000.
exp_time = 1.0e5
redshift = 0.05
nH_sim = 0.02
apec_model = TableApecModel(0.1, 11.5, 20000, thermal_broad=False)
abs_model = TBabsModel(nH_sim)
sphere = ds.sphere("c", (0.5, "Mpc"))
kT_sim = source.kT
Z_sim = source.Z
thermal_model = ThermalSourceModel(apec_model,
Zmet=Z_sim,
prng=source.prng)
photons = PhotonList.from_data_source(sphere, redshift, A, exp_time,
thermal_model)
D_A = photons.parameters["FiducialAngularDiameterDistance"]
norm_sim = sphere.quantities.total_quantity(em_field)
norm_sim *= 1.0e-14 / (4 * np.pi * D_A * D_A * (1. + redshift) *
(1. + redshift))
norm_sim = float(norm_sim.in_cgs())
v1, v2 = sphere.quantities.weighted_variance(v_field, em_field)
sigma_sim = float(v1.in_units("km/s"))
mu_sim = -float(v2.in_units("km/s"))
events = photons.project_photons("z",
absorb_model=abs_model,
prng=source.prng)
events = ACIS_I(events, rebin=False, convolve_psf=False, prng=source.prng)
events.write_spectrum("beta_model_evt.pi", clobber=True)
os.system("cp %s ." % events.parameters["ARF"])
os.system("cp %s ." % events.parameters["RMF"])
load_user_model(mymodel, "tbapec")
add_user_pars("tbapec", ["nH", "kT", "metallicity", "redshift", "norm"],
[0.01, 4.0, 0.2, redshift, norm_sim * 0.8],
parmins=[0.0, 0.1, 0.0, -20.0, 0.0],
parmaxs=[10.0, 20.0, 10.0, 20.0, 1.0e9],
parfrozen=[False, False, False, True, False])
load_pha("beta_model_evt.pi")
set_stat("cstat")
set_method("simplex")
ignore(":0.5, 8.0:")
set_model("tbapec")
fit()
set_covar_opt("sigma", 1.645)
covar()
res = get_covar_results()
assert np.abs(res.parvals[0] - nH_sim) < res.parmaxes[0]
assert np.abs(res.parvals[1] - kT_sim) < res.parmaxes[1]
assert np.abs(res.parvals[2] - Z_sim) < res.parmaxes[2]
assert np.abs(res.parvals[3] - norm_sim) < res.parmaxes[3]
os.chdir(curdir)
shutil.rmtree(tmpdir)
g0.xpos = maxpix[0] g0.ypos = maxpix[1] sh.freeze(g0.xpos, g0.ypos) expo.ampl = 1e-9 sh.freeze(expo) sh.thaw(g0.fwhm, g0.ampl) g0.fwhm = 10 g0.ampl = maxcoord[1] sh.fit() # In[57]: sh.thaw(g0.xpos, g0.ypos) sh.fit() sh.covar() sh.freeze(g0) data = sh.get_data_image().y - sh.get_model_image().y resid = SkyImage(data=data, wcs=ref_image.wcs) resid_smo6 = resid.smooth(radius=6) resid_smo6.show(vmin=-0.5, vmax=1, add_cbar=True) resid_table.append(resid_smo6) # In[58]: from astropy.stats import gaussian_fwhm_to_sigma coord = resid.wcs_pixel_to_skycoord(g0.xpos.val, g0.ypos.val) pix_scale = resid.wcs_pixel_scale()[0].deg sigma = g0.fwhm.val * pix_scale * gaussian_fwhm_to_sigma
def plaw_fit(alpha_sim):
tmpdir = tempfile.mkdtemp()
curdir = os.getcwd()
os.chdir(tmpdir)
bms = BetaModelSource()
ds = bms.ds
def _hard_emission(field, data):
return YTQuantity(1.0e-18, "s**-1*keV**-1")*data["density"]*data["cell_volume"]/mp
ds.add_field(("gas", "hard_emission"), function=_hard_emission, units="keV**-1*s**-1")
nH_sim = 0.02
abs_model = WabsModel(nH_sim)
A = YTQuantity(2000., "cm**2")
exp_time = YTQuantity(2.0e5, "s")
redshift = 0.01
sphere = ds.sphere("c", (100.,"kpc"))
plaw_model = PowerLawSourceModel(1.0, 0.01, 11.0, "hard_emission",
alpha_sim, prng=prng)
photons = PhotonList.from_data_source(sphere, redshift, A, exp_time,
plaw_model)
D_A = photons.parameters["FiducialAngularDiameterDistance"]
dist_fac = 1.0/(4.*np.pi*D_A*D_A*(1.+redshift)**3).in_cgs()
norm_sim = float((sphere["hard_emission"]).sum()*dist_fac.in_cgs())*(1.+redshift)
events = photons.project_photons("z", absorb_model=abs_model,
prng=bms.prng,
no_shifting=True)
events = ACIS_I(events, rebin=False, convolve_psf=False, prng=bms.prng)
events.write_spectrum("plaw_model_evt.pi", clobber=True)
os.system("cp %s ." % events.parameters["ARF"])
os.system("cp %s ." % events.parameters["RMF"])
load_user_model(mymodel, "wplaw")
add_user_pars("wplaw", ["nH", "norm", "redshift", "alpha"],
[0.01, norm_sim*1.1, redshift, 0.9],
parmins=[0.0, 0.0, 0.0, 0.1],
parmaxs=[10.0, 1.0e9, 10.0, 10.0],
parfrozen=[False, False, True, False])
load_pha("plaw_model_evt.pi")
set_stat("cstat")
set_method("simplex")
ignore(":0.6, 7.0:")
set_model("wplaw")
fit()
set_covar_opt("sigma", 1.645)
covar()
res = get_covar_results()
assert np.abs(res.parvals[0]-nH_sim) < res.parmaxes[0]
assert np.abs(res.parvals[1]-norm_sim) < res.parmaxes[1]
assert np.abs(res.parvals[2]-alpha_sim) < res.parmaxes[2]
os.chdir(curdir)
shutil.rmtree(tmpdir)
def simulate_null_images(img_file: str,
psf_file: str,
n_null_sims: int,
no_core: bool = False,
mcmciter: int = 5000,
**kwargs) -> None:
"""
Simulates a specified number of baseline images for a given input observation and a psf file
:param img_file: Path to the input image file
:param psf_file: Path to the psf image file
:param n_null_sims: Number of baseline replicates to be simulated
:param no_core: Setting this to True will only generate baseline replicates with a flat background while the default value includes a point source at the location of the core
:param mcmciter: The number of MCMC samples to draw for simulating the baselines
"""
print("Creating the null file")
clean()
set_stat("cstat")
set_method("simplex")
load_image(img_file)
load_psf("mypsf", psf_file)
set_psf(mypsf)
if no_core:
set_model(const2d.c0)
set_par(c0.c0, min=0)
else:
set_model(gauss2d.q1 + const2d.c0)
set_par(c0.c0, min=0)
# set_par(q1.fwhm,max=0.5)
guess(q1)
fit()
results = get_fit_results()
save("core_source_fit.save", clobber=True)
save_source("null_q1_c1.fits", clobber=True)
covar()
if no_core:
for i in range(n_null_sims):
fake()
save_image("sim_null_{}.fits".format(i), clobber=True)
clean()
return
normgauss1d.g1
g1.pos = q1.fwhm
g1.fwhm = get_covar_results().parmaxes[0]
# check if there is a valid upper bound.
print(get_covar_results())
if (get_covar_results().parmaxes[0] is None
or get_covar_results().parmins[1] is None
or get_covar_results().parmins[0] is None):
for i in range(n_null_sims):
fake()
save_image("sim_null_{}.fits".format(i), clobber=True)
clean()
return
# if not go for the regular
set_prior(q1.fwhm, g1)
set_sampler_opt("defaultprior", False)
set_sampler_opt("priorshape", [True, False, False, False, False])
set_sampler_opt("originalscale", [True, True, True, True, True])
if mcmciter < n_null_sims * 100:
mcmciter = n_null_sims * 100
# the following code throws an error sometimes #bug
try:
stats, accept, params = get_draws(1, niter=mcmciter)
except:
params = [np.repeat(q1.fwhm.val, mcmciter)]
# print('Simulating the null files')
for i in range(n_null_sims):
set_par(q1.fwhm, params[0][(i + 1) * 100 - 1])
fake()
save_image("sim_null_{}.fits".format(i), clobber=True)
save_all(outfile="lira_input_baseline_sim.log", clobber=True)
clean()
sau.set_stat('cstat')
# Ask for high-precision results
sau.set_method_opt('ftol', 1e-20)
sau.set_covar_opt('eps', 1e-20)
# Set start parameters close to simulation values to make the fit converge
sau.set_par('source.xpos', 101)
sau.set_par('source.ypos', 101)
sau.set_par('source.ampl', 1.1e3)
sau.set_par('source.fwhm', 10)
sau.set_par('background.c0', 1.1)
# Run fit and covariance estimation
# Results are automatically printed to the screen
sau.fit()
sau.covar()
# Sherpa uses fwhm instead of sigma as extension parameter ... need to convert
# http://cxc.harvard.edu/sherpa/ahelp/gauss2d.html
fwhm_to_sigma = 1. / np.sqrt(8 * np.log(2))
cov = sau.get_covar_results()
sigma = fwhm_to_sigma * cov.parvals[0]
sigma_err = fwhm_to_sigma * cov.parmaxes[0]
print('sigma: {0} +- {1}'.format(sigma, sigma_err))
# Compute correlation coefficient for sigma and norm
c = cov.extra_output
c_norm = c[3, 3]
c_sigma = fwhm_to_sigma ** 2 * c[0, 0]
c_norm_sigma = fwhm_to_sigma * c[0, 3]
corr_norm_sigma = c_norm_sigma / np.sqrt(c_norm * c_sigma)
def fit_sherpa(obsid_list,
redshift,
nH_Gal,
energy,
min_counts=25,
kT_guess=3,
Ab_guess=1,
fix_nH_Gal=True,
fix_abund=False,
find_errors=True):
spectra = []
for obs in obsid_list:
temp = glob.glob('xaf_*_' + obs + '.pi') # get spectra of regions
spectra.append(
temp
) # spectra will be made of lists which have xaf_*_obs.pi filenames - access with spectra[i][j]
spectra.sort()
num_obs = len(obsid_list)
num_reg = len(temp)
filename = 'spectra_wabs_mekal.dat'
results_file = open(filename, "w")
results_file.write(
'# Fit results for wabs*mekal (zeros indicate that no fitting was performed)\n'
)
results_file.write(
'# Reg_no. kT kT_loerr kT_hierr Z Z_loerr Z_hierr norm norm_loerr norm_hierr nH_Gal nH_loerr nH_hierr red_chisq total_counts num_bins\n'
)
for i in range(num_reg):
sherpa.clean() # clean everything
cnts = numpy.zeros(
num_obs
) # make array of zeros with index length same as num_obs to store counts
max_rate = numpy.zeros(num_obs) # max count rate [counts/s/keV]
data_set = 0 # data set number
good_src_ids = numpy.zeros(num_obs, dtype=int) - 1
for j in range(num_obs):
sherpa.load_pha(
data_set, spectra[j]
[i]) # load xaf_#_obs_####.pi and .arf and .rmf files.
sherpa.ignore_id(data_set, 0.0, energy[0])
sherpa.ignore_id(data_set, energy[1], None)
cnts[j] = sherpa.calc_data_sum(energy[0], energy[1], data_set)
cnt_rate = sherpa.get_rate(data_set, filter=True)
if len(cnt_rate) == 0:
max_rate[
j] = 0.0 # when few counts (<50), get_rate can return zero-length array
else:
max_rate[j] = numpy.max(cnt_rate)
sherpa.subtract(data_set) # subtract background
sherpa.set_source(
data_set, sherpa.xswabs.abs1 *
sherpa.xsmekal.plsm1) # 1 temperature mekal model fit
good_src_ids[j] = data_set
data_set += 1 # same run for region but different obs
# Filter out ignored obs
good_src_ids_indx = numpy.where(good_src_ids >= 0)
good_src_ids = good_src_ids[good_src_ids_indx]
max_rate = max_rate[good_src_ids_indx]
cnts = cnts[good_src_ids_indx]
totcnts = numpy.sum(cnts)
if totcnts >= min_counts:
print('Fitting spectra in region: ' + str(i))
abs1.nH = nH_Gal
abs1.cache = 0
if fix_nH_Gal:
sherpa.freeze(abs1.nH)
else:
sherpa.thaw(abs1.nH)
plsm1.kt = kT_guess
sherpa.thaw(plsm1.kt)
plsm1.Abundanc = Ab_guess
if fix_abund:
sherpa.freeze(plsm1.Abundanc)
else:
sherpa.thaw(plsm1.Abundanc)
plsm1.redshift = redshift
sherpa.freeze(plsm1.redshift)
plsm1.cache = 0
sherpa.fit()
fit_result = sherpa.get_fit_results()
red_chi2 = fit_result.rstat
num_bins = fit_result.numpoints
if fix_nH_Gal:
nH = nH_Gal
kT = fit_result.parvals[0]
if fix_abund:
Z = Ab_guess
norm = fit_result.parvals[1]
else:
Z = fit_result.parvals[1]
norm = fit_result.parvals[2]
else:
nH = fit_result.parvals[0]
kT = fit_result.parvals[1]
if fix_abund:
Z = Ab_guess
norm = fit_result.parvals[2]
else:
Z = fit_result.parvals[2]
norm = fit_result.parvals[3]
del fit_result
if find_errors:
sherpa.covar()
covar_result = sherpa.get_covar_results()
if fix_nH_Gal:
nH_loerr = 0.0
nH_hierr = 0.0
kT_loerr = covar_result.parmins[0]
kT_hierr = covar_result.parmaxes[0]
if fix_abund:
Z_loerr = 0.0
Z_hierr = 0.0
norm_loerr = covar_result.parmins[1]
norm_hierr = covar_result.parmaxes[1]
else:
Z_loerr = covar_result.parmins[1]
Z_hierr = covar_result.parmaxes[1]
norm_loerr = covar_result.parmins[2]
norm_hierr = covar_result.parmaxes[2]
else:
nH_loerr = covar_result.parmins[0]
nH_hierr = covar_result.parmaxes[0]
kT_loerr = covar_result.parmins[1]
kT_hierr = covar_result.parmaxes[1]
if fix_abund:
Z_loerr = 0.0
Z_hierr = 0.0
norm_loerr = covar_result.parmins[2]
norm_hierr = covar_result.parmaxes[2]
else:
Z_loerr = covar_result.parmins[2]
Z_hierr = covar_result.parmaxes[2]
norm_loerr = covar_result.parmins[3]
norm_hierr = covar_result.parmaxes[3]
del covar_result
# Check for failed errors (= None) and set them to +/- best-fit value
if not fix_nH_Gal:
if nH_loerr is None: nH_loerr = -nH # is was ==
if nH_hierr is None: nH_hierr = nH
if kT_loerr is None: kT_loerr = -kT
if kT_hierr is None: kT_hierr = kT
if not fix_abund:
if Z_loerr is None: Z_loerr = -Z
if Z_hierr is None: Z_hierr = Z
if norm_loerr is None: norm_loerr = -norm
if norm_hierr is None: norm_hierr = norm
else:
kT_loerr = 0.0
Z_loerr = 0.0
nH_loerr = 0.0
norm_loerr = 0.0
kT_hierr = 0.0
Z_hierr = 0.0
nH_hierr = 0.0
norm_hierr = 0.0
else: # if total counts < min_counts, just write zeros
print('\n Warning: no fit performed for for region: ' + str(i))
print(
'\n Spectra have insufficient counts after filtering or do not exist.'
)
print('\n --> All parameters for this region set to 0.0.')
kT = 0.0
Z = 0.0
nH = 0.0
norm = 0.0
kT_loerr = 0.0
Z_loerr = 0.0
nH_loerr = 0.0
norm_loerr = 0.0
kT_hierr = 0.0
Z_hierr = 0.0
nH_hierr = 0.0
norm_hierr = 0.0
red_chi2 = 0.0
num_bins = 0
reg_id = spectra[0][i].split(
'_'
) # Splits string after every underscore so that region number can be accessed. reg_id[1] is accessed because that is the region number after 'xaf'
results_file.write(
'%7r %7.4f %7.4f %7.4f %7.4f %7.4f %7.4f %6.4e %6.4e %6.4e %7.4f %7.4f %7.4f %7.4f %8.1f %8r\n'
% (int(reg_id[1]), kT, kT_loerr, kT_hierr, Z, Z_loerr, Z_hierr,
norm, norm_loerr, norm_hierr, nH, nH_loerr, nH_hierr, red_chi2,
totcnts, num_bins)) # Write all data to a file
results_file.close()
sau.set_stat('cstat')
# Ask for high-precision results
sau.set_method_opt('ftol', 1e-20)
sau.set_covar_opt('eps', 1e-20)
# Set start parameters close to simulation values to make the fit converge
sau.set_par('source.xpos', 101)
sau.set_par('source.ypos', 101)
sau.set_par('source.ampl', 1.1e3)
sau.set_par('source.fwhm', 10)
sau.set_par('background.c0', 1.1)
# Run fit and covariance estimation
# Results are automatically printed to the screen
sau.fit()
sau.covar()
# Sherpa uses fwhm instead of sigma as extension parameter ... need to convert
# http://cxc.harvard.edu/sherpa/ahelp/gauss2d.html
fwhm_to_sigma = 1. / np.sqrt(8 * np.log(2))
cov = sau.get_covar_results()
sigma = fwhm_to_sigma * cov.parvals[0]
sigma_err = fwhm_to_sigma * cov.parmaxes[0]
print('sigma: {0} +- {1}'.format(sigma, sigma_err))
# Compute correlation coefficient for sigma and norm
c = cov.extra_output
c_norm = c[3, 3]
c_sigma = fwhm_to_sigma**2 * c[0, 0]
c_norm_sigma = fwhm_to_sigma * c[0, 3]
corr_norm_sigma = c_norm_sigma / np.sqrt(c_norm * c_sigma)
def test_beta_model():
tmpdir = tempfile.mkdtemp()
curdir = os.getcwd()
os.chdir(tmpdir)
r_c = 20.0
beta = 1.0
exp_time = Quantity(500.0, "ks")
e = spec.generate_energies(exp_time, area, prng=prng)
beta_src = BetaModel(ra0, dec0, r_c, beta, e.size, prng=prng)
write_photon_list("beta",
"beta",
e.flux,
beta_src.ra,
beta_src.dec,
e,
overwrite=True)
instrument_simulator("beta_simput.fits",
"beta_evt.fits",
exp_time,
"hdxi", [ra0, dec0],
ptsrc_bkgnd=False,
instr_bkgnd=False,
foreground=False,
prng=prng)
inst = get_instrument_from_registry("hdxi")
arf = AuxiliaryResponseFile(inst["arf"])
cspec = ConvolvedSpectrum(spec, arf)
ph_flux = cspec.get_flux_in_band(0.5, 7.0)[0].value
S0 = 3.0 * ph_flux / (2.0 * np.pi * r_c * r_c)
write_radial_profile("beta_evt.fits",
"beta_evt_profile.fits", [ra0, dec0],
0.0,
100.0,
200,
ctr_type="celestial",
emin=0.5,
emax=7.0,
overwrite=True)
load_data(1, "beta_evt_profile.fits", 3,
["RMID", "SUR_BRI", "SUR_BRI_ERR"])
set_stat("chi2")
set_method("levmar")
set_source("beta1d.src")
src.beta = 1.0
src.r0 = 10.0
src.ampl = 0.8 * S0
freeze(src.xpos)
fit()
set_covar_opt("sigma", 1.645)
covar()
res = get_covar_results()
assert np.abs(res.parvals[0] - r_c) < res.parmaxes[0]
assert np.abs(res.parvals[1] - beta) < res.parmaxes[1]
assert np.abs(res.parvals[2] - S0) < res.parmaxes[2]
os.chdir(curdir)
shutil.rmtree(tmpdir)
def test_beta_model_flux():
tmpdir = tempfile.mkdtemp()
curdir = os.getcwd()
os.chdir(tmpdir)
r_c = 20.0
beta = 1.0
prng = 34
e = spec.generate_energies(exp_time, area, prng=prng)
beta_src = BetaModel(ra0, dec0, r_c, beta, e.size, prng=prng)
write_photon_list("beta",
"beta",
e.flux,
beta_src.ra,
beta_src.dec,
e,
overwrite=True)
instrument_simulator("beta_simput.fits",
"beta_evt.fits",
exp_time,
"acisi_cy0", [ra0, dec0],
ptsrc_bkgnd=False,
instr_bkgnd=False,
foreground=False,
roll_angle=37.0,
prng=prng)
ph_flux = spec.get_flux_in_band(0.5, 7.0)[0].value
S0 = 3.0 * ph_flux / (2.0 * np.pi * r_c * r_c)
wspec = spec.new_spec_from_band(0.5, 7.0)
make_exposure_map("beta_evt.fits",
"beta_expmap.fits",
wspec.emid.value,
weights=wspec.flux.value,
overwrite=True)
write_radial_profile("beta_evt.fits",
"beta_evt_profile.fits", [ra0, dec0],
0.0,
100.0,
200,
ctr_type="celestial",
emin=0.5,
emax=7.0,
expmap_file="beta_expmap.fits",
overwrite=True)
load_data(1, "beta_evt_profile.fits", 3,
["RMID", "SUR_FLUX", "SUR_FLUX_ERR"])
set_stat("chi2")
set_method("levmar")
set_source("beta1d.src")
src.beta = 1.0
src.r0 = 10.0
src.ampl = 0.8 * S0
freeze(src.xpos)
fit()
set_covar_opt("sigma", 1.645)
covar()
res = get_covar_results()
assert np.abs(res.parvals[0] - r_c) < res.parmaxes[0]
assert np.abs(res.parvals[1] - beta) < res.parmaxes[1]
assert np.abs(res.parvals[2] - S0) < res.parmaxes[2]
os.chdir(curdir)
shutil.rmtree(tmpdir)
nomposstr = '05h34m31.94s 22d00m52.2s'
header = fits.getheader(filename)
proj = wcs.Projection(header)
xc, yc = float(header['NAXIS1']) / 2., float(header['NAXIS2']) / 2.
ui.load_image(filename)
ui.notice2d('circle({0}, {1}, {2})'.format(xc, yc,
float(header['NAXIS2']) / 4.))
ui.set_source(ui.gauss2d.g1 + ui.gauss2d.g2)
g1.xpos = xc
g1.ypos = yc
g2.fwhm = g1.fwhm = 3.
ui.link(g2.xpos, g1.xpos)
ui.link(g2.ypos, g1.ypos)
g2.ampl = 50.
g1.ampl = 50.
ui.guess()
ui.fit()
ui.image_fit()
ui.covar()
conf = ui.get_covar_results()
conf_dict = dict([(n, (v, l, h)) for n, v, l, h in zip(
conf.parnames, conf.parvals, conf.parmins, conf.parmaxes)])
x, y = proj.toworld((conf_dict['g1.xpos'][0], conf_dict['g1.ypos'][0]))
xmin, ymin = proj.toworld((conf_dict['g1.xpos'][0] + conf_dict['g1.xpos'][1],
conf_dict['g1.ypos'][0] + conf_dict['g1.ypos'][1]))
xmax, ymax = proj.toworld((conf_dict['g1.xpos'][0] + conf_dict['g1.xpos'][2],
conf_dict['g1.ypos'][0] + conf_dict['g1.ypos'][2]))
nompos = positions.str2pos(nomposstr, proj)
print('{0} ({1}-{2}) vs {3}'.format(x, xmin, xmax, nompos[0][0][0]))
print('{0} ({1}-{2}) vs {3}'.format(y, ymin, ymax, nompos[0][0][1]))
def test_annulus():
tmpdir = tempfile.mkdtemp()
curdir = os.getcwd()
os.chdir(tmpdir)
r_in = 10.0
r_out = 30.0
e = spec.generate_energies(exp_time, area, prng=prng)
ann_src = AnnulusModel(ra0, dec0, r_in, r_out, e.size, prng=prng)
write_photon_list("ann",
"ann",
e.flux,
ann_src.ra,
ann_src.dec,
e,
overwrite=True)
instrument_simulator("ann_simput.fits",
"ann_evt.fits",
exp_time,
"hdxi", [ra0, dec0],
ptsrc_bkgnd=False,
instr_bkgnd=False,
foreground=False,
prng=prng)
inst = get_instrument_from_registry("hdxi")
arf = AuxiliaryResponseFile(inst["arf"])
cspec = ConvolvedSpectrum(spec, arf)
ph_flux = cspec.get_flux_in_band(0.5, 7.0)[0].value
S0 = ph_flux / (np.pi * (r_out**2 - r_in**2))
write_radial_profile("ann_evt.fits",
"ann_evt_profile.fits", [ra0, dec0],
1.1 * r_in,
0.9 * r_out,
100,
ctr_type="celestial",
emin=0.5,
emax=7.0,
overwrite=True)
load_data(1, "ann_evt_profile.fits", 3, ["RMID", "SUR_BRI", "SUR_BRI_ERR"])
set_stat("chi2")
set_method("levmar")
set_source("const1d.src")
src.c0 = 0.8 * S0
fit()
set_covar_opt("sigma", 1.645)
covar()
res = get_covar_results()
assert np.abs(res.parvals[0] - S0) < res.parmaxes[0]
os.chdir(curdir)
shutil.rmtree(tmpdir)
def test_point_source():
tmpdir = tempfile.mkdtemp()
curdir = os.getcwd()
os.chdir(tmpdir)
nH_sim = 0.02
norm_sim = 1.0e-4
alpha_sim = 0.95
redshift = 0.02
exp_time = (100., "ks")
area = (3000., "cm**2")
wcs = create_dummy_wcs()
ebins = np.linspace(0.1, 11.5, 2001)
emid = 0.5*(ebins[1:]+ebins[:-1])
spec = norm_sim*(emid*(1.0+redshift))**(-alpha_sim)
de = np.diff(ebins)[0]
abs_model = TBabsModel(nH_sim)
events = EventList.create_empty_list(exp_time, area, wcs)
positions = [(30.01, 45.0)]
new_events = events.add_point_sources(positions, ebins, spec, prng=prng,
absorb_model=abs_model)
new_events = ACIS_S(new_events, prng=prng)
scalex = float(np.std(new_events['xpix'])*sigma_to_fwhm*new_events.parameters["dtheta"])
scaley = float(np.std(new_events['ypix'])*sigma_to_fwhm*new_events.parameters["dtheta"])
psf_scale = ACIS_S.psf_scale
assert (scalex - psf_scale)/psf_scale < 0.01
assert (scaley - psf_scale)/psf_scale < 0.01
new_events.write_spectrum("point_source_evt.pi", clobber=True)
os.system("cp %s ." % new_events.parameters["ARF"])
os.system("cp %s ." % new_events.parameters["RMF"])
load_user_model(mymodel, "tplaw")
add_user_pars("tplaw", ["nH", "norm", "redshift", "alpha"],
[0.01, norm_sim*0.8, redshift, 0.9],
parmins=[0.0, 0.0, 0.0, 0.1],
parmaxs=[10.0, 1.0e9, 10.0, 10.0],
parfrozen=[False, False, True, False])
load_pha("point_source_evt.pi")
set_stat("cstat")
set_method("simplex")
ignore(":0.5, 9.0:")
set_model("tplaw")
fit()
set_covar_opt("sigma", 1.6)
covar()
res = get_covar_results()
assert np.abs(res.parvals[0]-nH_sim) < res.parmaxes[0]
assert np.abs(res.parvals[1]-norm_sim/de) < res.parmaxes[1]
assert np.abs(res.parvals[2]-alpha_sim) < res.parmaxes[2]
os.chdir(curdir)
shutil.rmtree(tmpdir)
import sherpa.astro.ui as ui from spec import load_data, report_results # Load data x, y, y_err = load_data() ui.load_arrays(1, x, y, y_err) # Set up the model ui.set_model(ui.powlaw1d.pl) pl.gamma, pl.ampl = 2, 1e-12 # Perform fit ui.fit() # Compute best-fit parameters ui.covar() # Compute covariance matrix (i.e. errors) # ui.conf() # Compute profile errors # ui.show_all() # Print a very nice summary of your session to less # Report results fr = ui.get_fit_results() cr = ui.get_covar_results() package = "sherpa" gamma, norm = fr.parvals chi2 = fr.statval gamma_err, norm_err = cr.parmaxes cov = cr.extra_output[1, 0] corr = cov / (norm_err * gamma_err) report_results(package, norm, norm_err, gamma, gamma_err, chi2, cov, corr)
