def test_cstat_rsppha():
"""What does CSTAT calculate when there is an RSP+PHA instrument model.
This includes the AREASCAL when evaluating the model.
See Also
--------
test_cstat_nophamodel, test_cstat_arfpha, test_cstat_rmfpha
"""
dset, mdl, expected = setup_likelihood(scale=True)
# use the full channel grid; the energy grid has to be
# "the same" as the channel values since the model
# has a dependency on the independent axis
#
egrid = 1.0 * np.concatenate((dset.channel, [dset.channel.max() + 1]))
arf = make_arf(energ_lo=egrid[:-1], energ_hi=egrid[1:])
rmf = make_ideal_rmf(e_min=egrid[:-1], e_max=egrid[1:])
mdl_ascal = RSPModelPHA(arf, rmf, dset, mdl)
stat = CStat()
sval_ascal = stat.calc_stat(dset, mdl_ascal)
assert_allclose(sval_ascal[0], expected)
def test_rspmodelpha_delta_call(ignore):
"""What happens calling a rsp with a pha (RMF is a delta fn)?
The ignore value gives the channel to ignore (counting from 0).
"""
exposure = 200.1
estep = 0.025
egrid = np.arange(0.1, 0.8, estep)
elo = egrid[:-1]
ehi = egrid[1:]
specresp = 2.4 * np.ones(elo.size, dtype=np.float32)
specresp[2:5] = 0.0
specresp[16:19] = 3.2
adata = create_arf(elo, ehi, specresp, exposure=exposure)
rdata = create_delta_rmf(elo, ehi, e_min=elo, e_max=ehi)
nchans = elo.size
constant = 2.3
mdl = Const1D('flat')
mdl.c0 = constant
channels = np.arange(1, nchans + 1, dtype=np.int16)
counts = np.ones(nchans, dtype=np.int16)
pha = DataPHA('test-pha',
channel=channels,
counts=counts,
exposure=exposure)
pha.set_rmf(rdata)
# force energy units (only needed if ignore is set)
pha.set_analysis('energy')
if ignore is not None:
de = estep * 0.9
e0 = egrid[ignore]
pha.notice(lo=e0, hi=e0 + de, ignore=True)
# The assert are intended to help people reading this
# code rather than being a useful check that the code
# is working.
mask = [True] * nchans
mask[ignore] = False
assert (pha.mask == mask).all()
wrapped = RSPModelPHA(adata, rdata, pha, mdl)
# The model is evaluated on the RMF grid, not whatever
# is sent in. It is also integrated across the bins,
# which is why there is a multiplication by the
# grid width (for this constant model).
#
# Note that the filter doesn't change the grid.
#
de = egrid[1:] - egrid[:-1]
expected = constant * specresp * de
out = wrapped([4, 5])
assert_allclose(out, expected)
def test_rspmodelpha_matrix_call(ignore):
"""What happens calling a rsp with a pha (RMF is a matrix)?
The ignore value gives the channel to ignore (counting from 0).
"""
exposure = 200.1
rdata = create_non_delta_rmf()
specresp = create_non_delta_specresp()
elo = rdata.energ_lo
ehi = rdata.energ_hi
adata = create_arf(elo, ehi, specresp, exposure=exposure)
nchans = rdata.e_min.size
constant = 22.3
slope = -1.2
mdl = Polynom1D('sloped')
mdl.c0 = constant
mdl.c1 = slope
channels = np.arange(1, nchans + 1, dtype=np.int16)
counts = np.ones(nchans, dtype=np.int16)
pha = DataPHA('test-pha',
channel=channels,
counts=counts,
exposure=exposure)
pha.set_rmf(rdata)
# force energy units (only needed if ignore is set)
pha.set_analysis('energy')
if ignore is not None:
e0 = rdata.e_min[ignore]
e1 = rdata.e_max[ignore]
de = 0.9 * (e1 - e0)
pha.notice(lo=e0, hi=e0 + de, ignore=True)
# The assert are intended to help people reading this
# code rather than being a useful check that the code
# is working.
mask = [True] * nchans
mask[ignore] = False
assert (pha.mask == mask).all()
wrapped = RSPModelPHA(adata, rdata, pha, mdl)
# The filter does not change the grid
modvals = specresp * mdl(rdata.energ_lo, rdata.energ_hi)
matrix = get_non_delta_matrix()
expected = np.matmul(modvals, matrix)
out = wrapped([4, 5])
assert_allclose(out, expected)
def test_rsp1d_delta_pha_zero_energy_bin():
"What happens when the first bin starts at 0, with replacement"
ethresh = 2.0e-7
# PHA and ARF have different exposure ties
exposure1 = 0.1
exposure2 = 2.4
egrid = np.asarray([0.0, 0.1, 0.2, 0.4, 0.5, 0.7, 0.8])
elo = egrid[:-1]
ehi = egrid[1:]
specresp = np.asarray([10.2, 9.8, 10.0, 12.0, 8.0, 10.0])
with warnings.catch_warnings(record=True) as ws:
warnings.simplefilter("always")
adata = create_arf(elo,
ehi,
specresp,
exposure=exposure1,
ethresh=ethresh)
validate_zero_replacement(ws, 'ARF', 'user-arf', ethresh)
with warnings.catch_warnings(record=True) as ws:
warnings.simplefilter("always")
rdata = create_delta_rmf(elo, ehi, ethresh=ethresh)
validate_zero_replacement(ws, 'RMF', 'delta-rmf', ethresh)
channels = np.arange(1, 7, dtype=np.int16)
counts = np.ones(6, dtype=np.int16)
pha = DataPHA('test-pha',
channel=channels,
counts=counts,
exposure=exposure2)
pha.set_rmf(rdata)
pha.set_arf(adata)
pha.set_analysis('energy')
mdl = MyPowLaw1D()
tmdl = PowLaw1D()
wrapped = RSPModelPHA(adata, rdata, pha, mdl)
out = wrapped([0.1, 0.2])
elo[0] = ethresh
expected = specresp * tmdl(elo, ehi)
assert_allclose(out, expected)
assert not np.isnan(out[0])
def test_rspmodelpha_matrix_call_xspec():
"""Check XSPEC constant is invariant to wavelength/energy setting.
As XSPEC models internally convert from Angstrom to keV,
do a simple check here.
"""
exposure = 200.1
rdata = create_non_delta_rmf()
specresp = create_non_delta_specresp()
adata = create_arf(rdata.energ_lo,
rdata.energ_hi,
specresp,
exposure=exposure)
constant = 2.3
mdl = XSconstant('flat')
mdl.factor = constant
nchans = rdata.e_min.size
channels = np.arange(1, nchans + 1, dtype=np.int16)
counts = np.ones(nchans, dtype=np.int16)
pha = DataPHA('test-pha',
channel=channels,
counts=counts,
exposure=exposure)
# The set_arf call isn't necessary, but leave in
pha.set_arf(adata)
pha.set_rmf(rdata)
# The XSPEC models are evaluated on an energy grid, even when
# the analysis setting is wavelength. Also, unlike the Sherpa
# Constant model, the XSPEC XSconstant model is defined
# over the integrated bin, so no correction is needed for the
# bin width.
#
modvals = constant * specresp
matrix = get_non_delta_matrix()
expected = np.matmul(modvals, matrix)
wrapped = RSPModelPHA(adata, rdata, pha, mdl)
pha.set_analysis('wave')
out_wl = wrapped([4, 5])
assert_allclose(out_wl, expected)
pha.set_analysis('energy')
out_en = wrapped([4, 5])
assert_allclose(out_en, expected)
def test_rspmodelpha_delta_call_wave():
"""What happens calling a rsp with a pha (RMF is a delta fn)? Wavelength.
Unlike the energy case no bins are ignored, as this code path
has already been tested.
"""
exposure = 200.1
estep = 0.025
egrid = np.arange(0.1, 0.8, estep)
elo = egrid[:-1]
ehi = egrid[1:]
specresp = 2.4 * np.ones(elo.size, dtype=np.float32)
specresp[2:5] = 0.0
specresp[16:19] = 3.2
adata = create_arf(elo, ehi, specresp, exposure=exposure)
rdata = create_delta_rmf(elo, ehi, e_min=elo, e_max=ehi)
nchans = elo.size
constant = 2.3
mdl = Const1D('flat')
mdl.c0 = constant
channels = np.arange(1, nchans + 1, dtype=np.int16)
counts = np.ones(nchans, dtype=np.int16)
pha = DataPHA('test-pha',
channel=channels,
counts=counts,
exposure=exposure)
pha.set_rmf(rdata)
pha.set_analysis('wave')
wrapped = RSPModelPHA(adata, rdata, pha, mdl)
# Note that this is a Sherpa model, so it's normalization is
# per unit x axis, so when integrated here the bins are in
# Angstroms, so the bin width to multiply by is
# Angstroms, not keV.
#
dl = (DataPHA._hc / elo) - (DataPHA._hc / ehi)
expected = constant * specresp * dl
out = wrapped([4, 5])
assert_allclose(out, expected)
def test_rspmodelpha_delta_call_channel():
"""What happens calling a rsp with a pha (RMF is a delta fn)? Channels.
I am not convinced I understand the bin width calculation here,
as it doesn't seem to match the wavelength case.
"""
exposure = 200.1
estep = 0.025
egrid = np.arange(0.1, 0.8, estep)
elo = egrid[:-1]
ehi = egrid[1:]
specresp = 2.4 * np.ones(elo.size, dtype=np.float32)
specresp[2:5] = 0.0
specresp[16:19] = 3.2
adata = create_arf(elo, ehi, specresp, exposure=exposure)
rdata = create_delta_rmf(elo, ehi, e_min=elo, e_max=ehi)
nchans = elo.size
constant = 2.3
mdl = Const1D('flat')
mdl.c0 = constant
channels = np.arange(1, nchans + 1, dtype=np.int16)
counts = np.ones(nchans, dtype=np.int16)
pha = DataPHA('test-pha',
channel=channels,
counts=counts,
exposure=exposure)
pha.set_rmf(rdata)
pha.set_analysis('channel')
wrapped = RSPModelPHA(adata, rdata, pha, mdl)
# Since this is channels you might expect the bin width to be 1,
# but it is actually still dE.
#
de = ehi - elo
expected = constant * specresp * de
out = wrapped([4, 5])
assert_allclose(out, expected)
def prepare_spectra(group, nH, add_gal, redshift):
pha = read_pha("core_spectrum.pi")
pha.set_analysis("energy")
pha.notice(0.5, 7.0)
tabs = ~pha.mask
pha.group_counts(group, tabStops=tabs)
x = pha.get_x()
x = pha.apply_filter(x, pha._middle)
y = pha.get_y(filter=True)
pha.set_analysis("energy")
model = xsphabs.abs1 * powlaw1d.srcp1
print("Fitting the spectrum")
zFlag = False
if (nH is not None) and (nH > 0.0):
if add_gal == 1:
model = xsphabs.gal * xszphabs.abs1 * powlaw1d.srcp
gal.nH = nH
freeze(gal.nH)
zFlag = True
else:
model = xsphabs.abs1 * powlaw1d.srcp1
abs1.nH = nH
freeze(abs1.nH)
else:
model = xszphabs.abs1 * powlaw1d.srcp1
zFlag = True
if zFlag is True and add_gal == 1:
# print('REDSHIFT',redshift)
abs1.redshift = redshift
freeze(abs1.redshift)
full_model = RSPModelPHA(pha.get_arf(), pha.get_rmf(), pha, pha.exposure * model)
print(full_model)
fit = Fit(pha, full_model, method=MonCar(), stat=WStat())
res = fit.fit()
print(res.format())
print(fit.est_errors())
# calculate the p-value for wstat
mplot2 = ModelPlot()
mplot2.prepare(pha, full_model)
miu = mplot2.y * pha.exposure * 0.0146
obs = y * pha.exposure * 0.0146
c, ce, cv = gof_cstat(miu, obs)
print(f"C0={c},C_e={ce},C_v={cv}")
zval = (fit.calc_stat() - ce) / np.sqrt(cv)
if zval > 0:
pval = special.erfc(zval / np.sqrt(2))
else:
pval = special.erf(abs(zval) / np.sqrt(2))
print(f"p-value for wstat = {pval}")
set_data(pha)
set_model(model)
save_chart_spectrum("core_flux_chart.dat", elow=0.5, ehigh=7.0)
# save_chart_spectrum("core_flux_chart.rdb",format='text/tsv', elow=0.5, ehigh=7.0)
save_spectrum_rdb("core_flux_chart.dat")
def prepare_spectra(nH: float,
group: int = 1,
add_gal: bool = False,
redshift: Optional[float] = None,
**kwargs) -> float:
"""
Fit the spectra using an absorbed powerlaw model using the Wstat statistic. The function also returns a p-value for the gof.
:param nH: The galactic absorption column density in units of 10^22 /cm3
:param group: The number of counts per energy bin
:param add_gal: Setting this to True would add an intrinsic abrosption column density along side the galactic one
:param redshift: The redshift to use in the fit. Only takes effect if add_gal is set to True
...
:return: Returns the p-value of the gof. The null hypothesis states that the model and the observation differ while alternate says that the model explains the data
"""
pha = read_pha("core_spectrum.pi")
pha.set_analysis("energy")
pha.notice(0.5, 7.0)
tabs = ~pha.mask
pha.group_counts(group, tabStops=tabs)
x = pha.get_x()
x = pha.apply_filter(x, pha._middle)
y = pha.get_y(filter=True)
pha.set_analysis("energy")
model = xsphabs.abs1 * powlaw1d.srcp1
print("Fitting the spectrum")
zFlag = False
if (nH is not None) and (nH > 0.0):
if add_gal == 1:
model = xsphabs.gal * xszphabs.abs1 * powlaw1d.srcp
gal.nH = nH
freeze(gal.nH)
zFlag = True
else:
model = xsphabs.abs1 * powlaw1d.srcp1
abs1.nH = nH
freeze(abs1.nH)
else:
model = xszphabs.abs1 * powlaw1d.srcp1
zFlag = True
if zFlag is True and add_gal == 1:
# print('REDSHIFT',redshift)
abs1.redshift = redshift
freeze(abs1.redshift)
full_model = RSPModelPHA(pha.get_arf(), pha.get_rmf(), pha,
pha.exposure * model)
print(full_model)
fit = Fit(pha, full_model, method=MonCar(), stat=WStat())
res = fit.fit()
print(res.format())
print(fit.est_errors())
# calculate the p-value for wstat
mplot2 = ModelPlot()
mplot2.prepare(pha, full_model)
miu = mplot2.y * pha.exposure * 0.0146
obs = y * pha.exposure * 0.0146
c, ce, cv = SpecUtils.estimate_gof_cstat(miu, obs)
#print(f"C0={c},C_e={ce},C_v={cv}")
zval = (fit.calc_stat() - ce) / np.sqrt(cv)
if zval > 0:
pval = special.erfc(zval / np.sqrt(2))
else:
pval = special.erf(abs(zval) / np.sqrt(2))
print(f"p-value for wstat = {pval}")
set_data(pha)
set_model(model)
save_chart_spectrum("core_flux_chart.dat", elow=0.5, ehigh=7.0)
# save_chart_spectrum("core_flux_chart.rdb",format='text/tsv', elow=0.5, ehigh=7.0)
SAOTraceUtils.save_spectrum_rdb("core_flux_chart.dat")
return pval
plt.ylim(1e4, 3e6)
plt.xlim(0, 10)
plt.xlabel('Energy (keV)')
plt.ylabel('Count / keV')
savefig('rspmodelnopha_energy.png')
from sherpa.astro.io import read_pha
from sherpa.astro.instrument import RSPModelPHA
pha2 = read_pha('3c273.pi')
arf2 = pha2.get_arf()
rmf2 = pha2.get_rmf()
mdl2 = PowLaw1D('mdl2')
inst2 = RSPModelPHA(arf2, rmf2, pha2, mdl2)
report("inst2")
dump("inst2([]).size")
pha2.set_analysis('energy')
report('pha2.get_filter()')
report('pha2.get_filter_expr()')
pha2.notice(0.5, 7.0)
report('pha2.get_filter()')
report('pha2.get_filter_expr()')
dump("pha2.grouped")
# pha2.ungroup()
# report('pha2.get_filter_expr()')
