def read(cls, filename, offset='0.5 deg'):
"""Read from a FITS file.
Compute RMF at 0.5 deg offset on fly.
Parameters
----------
filename : `str`
File containing the IRFs
"""
filename = str(make_path(filename))
with fits.open(filename, memmap=False) as hdulist:
aeff = EffectiveAreaTable.from_hdulist(hdulist=hdulist)
edisp = EnergyDispersion2D.read(filename, hdu='ENERGY DISPERSION')
bkg = BgRateTable.from_hdulist(hdulist=hdulist)
psf = Psf68Table.from_hdulist(hdulist=hdulist)
sens = SensitivityTable.from_hdulist(hdulist=hdulist)
# Create rmf with appropriate dimensions (e_reco->bkg, e_true->area)
e_reco_min = bkg.energy.lo[0]
e_reco_max = bkg.energy.hi[-1]
e_reco_bin = bkg.energy.nbins
e_reco_axis = EnergyBounds.equal_log_spacing(
e_reco_min,
e_reco_max,
e_reco_bin,
'TeV',
)
e_true_min = aeff.energy.lo[0]
e_true_max = aeff.energy.hi[-1]
e_true_bin = aeff.energy.nbins
e_true_axis = EnergyBounds.equal_log_spacing(
e_true_min,
e_true_max,
e_true_bin,
'TeV',
)
rmf = edisp.to_energy_dispersion(
offset=offset,
e_reco=e_reco_axis,
e_true=e_true_axis,
)
return cls(aeff=aeff,
bkg=bkg,
edisp=edisp,
psf=psf,
sens=sens,
rmf=rmf)
def read(cls, filename, offset='0.5 deg'):
"""Read from a FITS file.
Compute RMF at 0.5 deg offset on fly.
Parameters
----------
filename : `str`
File containing the IRFs
"""
filename = str(make_path(filename))
with fits.open(filename, memmap=False) as hdulist:
aeff = EffectiveAreaTable.from_hdulist(hdulist=hdulist)
edisp = EnergyDispersion2D.read(filename, hdu='ENERGY DISPERSION')
bkg = BgRateTable.from_hdulist(hdulist=hdulist)
psf = Psf68Table.from_hdulist(hdulist=hdulist)
sens = SensitivityTable.from_hdulist(hdulist=hdulist)
# Create rmf with appropriate dimensions (e_reco->bkg, e_true->area)
e_reco_min = bkg.energy.lo[0]
e_reco_max = bkg.energy.hi[-1]
e_reco_bin = bkg.energy.nbins
e_reco_axis = EnergyBounds.equal_log_spacing(
e_reco_min, e_reco_max, e_reco_bin, 'TeV',
)
e_true_min = aeff.energy.lo[0]
e_true_max = aeff.energy.hi[-1]
e_true_bin = aeff.energy.nbins
e_true_axis = EnergyBounds.equal_log_spacing(
e_true_min, e_true_max, e_true_bin, 'TeV',
)
rmf = edisp.to_energy_dispersion(
offset=offset, e_reco=e_reco_axis, e_true=e_true_axis,
)
return cls(
aeff=aeff,
bkg=bkg,
edisp=edisp,
psf=psf,
sens=sens,
rmf=rmf
)
def load_irf(self):
filename = os.path.join(self.outdir, 'irf.fits.gz')
with fits.open(filename, memmap=False) as hdulist:
aeff = EffectiveAreaTable.from_hdulist(hdulist=hdulist)
edisp = EnergyDispersion2D.read(filename, hdu="ENERGY DISPERSION")
bkg_fits_table = hdulist["BACKGROUND"]
bkg_table = Table.read(bkg_fits_table)
energy_lo = bkg_table["ENERG_LO"].quantity
energy_hi = bkg_table["ENERG_HI"].quantity
bkg = bkg_table["BGD"].quantity
axes = [
BinnedDataAxis(
energy_lo, energy_hi, interpolation_mode="log", name="energy"
)
]
bkg = BkgData(data=NDDataArray(axes=axes, data=bkg))
# Create rmf with appropriate dimensions (e_reco->bkg, e_true->area)
e_reco_min = bkg.energy.lo[0]
e_reco_max = bkg.energy.hi[-1]
e_reco_bin = bkg.energy.nbins
e_reco_axis = EnergyBounds.equal_log_spacing(
e_reco_min, e_reco_max, e_reco_bin, "TeV"
)
e_true_min = aeff.energy.lo[0]
e_true_max = aeff.energy.hi[-1]
e_true_bin = aeff.energy.nbins
e_true_axis = EnergyBounds.equal_log_spacing(
e_true_min, e_true_max, e_true_bin, "TeV"
)
# Fake offset...
rmf = edisp.to_energy_dispersion(
offset=0.5 * u.deg, e_reco=e_reco_axis, e_true=e_true_axis
)
self.irf = Irf(bkg=bkg, aeff=aeff, rmf=rmf)
