Ejemplo n.º 1
0
def make_map_background_irf_with_symmetry(fpi, symmetry="constant"):
    axis = MapAxis.from_edges([0.1, 1, 10],
                              name="energy",
                              unit="TeV",
                              interp="log")
    return make_map_background_irf(
        pointing=fpi,
        ontime="42 s",
        bkg=bkg_3d_custom(symmetry),
        geom=WcsGeom.create(npix=(3, 3),
                            binsz=4,
                            axes=[axis],
                            skydir=fpi.radec),
    )
Ejemplo n.º 2
0
def test_make_map_background_irf(bkg_3d, pars, fixed_pointing_info):
    m = make_map_background_irf(
        pointing=fixed_pointing_info,
        ontime="42 s",
        bkg=bkg_3d,
        geom=geom(
            map_type=pars["map_type"],
            ebounds=pars["ebounds"],
            skydir=fixed_pointing_info.radec,
        ),
        oversampling=10,
    )

    assert m.data.shape == pars["shape"]
    assert m.unit == ""
    assert_allclose(m.data.sum(), pars["sum"], rtol=1e-5)
Ejemplo n.º 3
0
offset = Angle("2 deg")

# In[ ]:

exposure = make_map_exposure_true_energy(pointing=pointing.radec,
                                         livetime=livetime,
                                         aeff=irfs["aeff"],
                                         geom=geom)
exposure.slice_by_idx({
    "energy": 3
}).plot(add_cbar=True)

# In[ ]:

background = make_map_background_irf(pointing=pointing,
                                     ontime=livetime,
                                     bkg=irfs["bkg"],
                                     geom=geom)
background.slice_by_idx({
    "energy": 3
}).plot(add_cbar=True)

# In[ ]:

psf = irfs["psf"].to_energy_dependent_table_psf(theta=offset)
psf_kernel = PSFKernel.from_table_psf(psf, geom, max_radius=0.3 * u.deg)
psf_kernel.psf_kernel_map.sum_over_axes().plot(stretch="log")

# In[ ]:

energy = axis.edges
edisp = irfs["edisp"].to_energy_dispersion(offset,
Ejemplo n.º 4
0
def simulate_dataset(
    skymodel,
    geom,
    pointing,
    irfs,
    livetime=1 * u.h,
    offset=0 * u.deg,
    max_radius=0.8 * u.deg,
    random_state="random-seed",
):
    """Simulate a 3D dataset.

    Simulate a source defined with a sky model for a given pointing,
    geometry and irfs for a given exposure time.
    This will return a dataset object which includes the counts cube,
    the exposure cube, the psf cube, the background model and the sky model.

    Parameters
    ----------
    skymodel : `~gammapy.modeling.models.SkyModel`
        Background model map
    geom : `~gammapy.maps.WcsGeom`
        Geometry object for the observation
    pointing : `~astropy.coordinates.SkyCoord`
        Pointing position
    irfs : dict
        Irfs used for simulating the observation
    livetime : `~astropy.units.Quantity`
        Livetime exposure of the simulated observation
    offset : `~astropy.units.Quantity`
        Offset from the center of the pointing position.
        This is used for the PSF and Edisp estimation
    max_radius : `~astropy.coordinates.Angle`
        The maximum radius of the PSF kernel.
    random_state: {int, 'random-seed', 'global-rng', `~numpy.random.RandomState`}
        Defines random number generator initialisation.

    Returns
    -------
    dataset : `~gammapy.cube.MapDataset`
        A dataset of the simulated observation.
    """
    background = make_map_background_irf(
        pointing=pointing, ontime=livetime, bkg=irfs["bkg"], geom=geom
    )

    background_model = BackgroundModel(background)

    psf = irfs["psf"].to_energy_dependent_table_psf(theta=offset)
    psf_kernel = PSFKernel.from_table_psf(psf, geom, max_radius=max_radius)

    exposure = make_map_exposure_true_energy(
        pointing=pointing, livetime=livetime, aeff=irfs["aeff"], geom=geom
    )

    if "edisp" in irfs:
        energy = geom.axes[0].edges
        edisp = irfs["edisp"].to_energy_dispersion(offset, e_reco=energy, e_true=energy)
    else:
        edisp = None

    dataset = MapDataset(
        model=skymodel,
        exposure=exposure,
        background_model=background_model,
        psf=psf_kernel,
        edisp=edisp,
    )

    npred_map = dataset.npred()
    rng = get_random_state(random_state)
    counts = rng.poisson(npred_map.data)
    dataset.counts = WcsNDMap(geom, counts)

    return dataset