def simulate_spectrum_dataset(model, random_state=0):
edges = np.logspace(-0.5, 1.5, 21) * u.TeV
energy_axis = MapAxis.from_edges(edges, interp="log", name="energy")
aeff = EffectiveAreaTable.from_parametrization(energy=edges).to_region_map()
bkg_model = SkyModel(
spectral_model=PowerLawSpectralModel(
index=2.5, amplitude="1e-12 cm-2 s-1 TeV-1"
),
name="background",
)
bkg_model.spectral_model.amplitude.frozen = True
bkg_model.spectral_model.index.frozen = True
geom = RegionGeom(region=None, axes=[energy_axis])
acceptance = RegionNDMap.from_geom(geom=geom, data=1)
edisp = EDispKernelMap.from_diagonal_response(
energy_axis=energy_axis,
energy_axis_true=energy_axis.copy(name="energy_true"),
geom=geom
)
dataset = SpectrumDatasetOnOff(
aeff=aeff, livetime=100 * u.h, acceptance=acceptance, acceptance_off=5, edisp=edisp
)
dataset.models = bkg_model
bkg_npred = dataset.npred_sig()
dataset.models = model
dataset.fake(random_state=random_state, background_model=bkg_npred)
return dataset
def test_npred_no_edisp(self):
const = 1 * u.Unit("cm-2 s-1 TeV-1")
model = SkyModel(spectral_model=ConstantSpectralModel(const=const))
livetime = 1 * u.s
e_reco = self.on_counts.geom.axes[0].edges
aeff = EffectiveAreaTable(e_reco[:-1], e_reco[1:], np.ones(4) * u.cm ** 2)
dataset = SpectrumDatasetOnOff(
counts=self.on_counts,
counts_off=self.off_counts,
aeff=aeff,
models=model,
livetime=livetime,
)
energy = aeff.energy.edges
expected = aeff.data.data[0] * (energy[-1] - energy[0]) * const * livetime
assert_allclose(dataset.npred_sig().data.sum(), expected.value)
def test_npred_no_edisp(self):
const = 1 * u.Unit("cm-2 s-1 TeV-1")
model = SkyModel(spectral_model=ConstantSpectralModel(const=const))
livetime = 1 * u.s
aeff = RegionNDMap.create(region=self.on_region,
unit="cm2",
axes=[self.e_reco.copy(name="energy_true")])
aeff.data += 1
dataset = SpectrumDatasetOnOff(
counts=self.on_counts,
counts_off=self.off_counts,
aeff=aeff,
models=model,
livetime=livetime,
)
energy = aeff.geom.axes[0].edges
expected = aeff.data[0] * (energy[-1] - energy[0]) * const * livetime
assert_allclose(dataset.npred_sig().data.sum(), expected.value)