get_irfs_features#

gammapy.data.get_irfs_features(observations, energy_true, position=None, fixed_offset=None, names=None, containment_fraction=0.68, apply_standard_scaler=False)[source]#

Get features from IRFs properties at a given position. Used for observations clustering.

Parameters:

observationsObservations: Container holding a list of Observation.
energy_trueQuantity: Energy true at which to compute the containment radius.
positionSkyCoord, optional: Sky position. Default is None.
fixed_offsetAngle, optional: Offset calculated from the pointing position. Default is None. If neither the position nor the fixed_offset is specified, it uses the position of the center of the map by default.
names{“edisp-bias”, “edisp-res”, “psf-radius”}: IRFs properties to be considered. Default is None. If None, all the features are computed.
containment_fractionfloat, optional: Containment_fraction to compute the psf-radius. Default is 68%.
apply_standard_scalerbool, optional: Compute standardize features by removing the mean and scaling to unit variance. Default is False.

Returns:

featuresTable: Features table.

Examples

Compute the IRF features for “edisp-bias”, “edisp-res” and “psf-radius” at 1 TeV:

>>> from gammapy.data.utils import get_irfs_features
>>> from gammapy.data import DataStore
>>> from gammapy.utils.cluster import standard_scaler
>>> from astropy.coordinates import SkyCoord
>>> import astropy.units as u

>>> selection = dict(
...     type="sky_circle",
...     frame="icrs",
...     lon="329.716 deg",
...     lat="-30.225 deg",
...     radius="2 deg",
... )

>>> data_store = DataStore.from_dir("$GAMMAPY_DATA/hess-dl3-dr1/")
>>> obs_table = data_store.obs_table.select_observations(selection)
>>> obs = data_store.get_observations(obs_table["OBS_ID"][:3])

>>> position = SkyCoord(329.716 * u.deg, -30.225 * u.deg, frame="icrs")
>>> names = ["edisp-bias", "edisp-res", "psf-radius"]
>>> features_irfs = get_irfs_features(
...     obs,
...     energy_true="1 TeV",
...     position=position,
...     names=names,
... )

>>> print(features_irfs)
     edisp-bias     obs_id      edisp-res           psf-radius
                                                   deg
    ------------------- ------ ------------------- -------------------
    0.11587179071752986  33787   0.368346217294295 0.14149953611195087
    0.04897634344908595  33788 0.33983991887701287 0.11553325504064559
      0.033176650892097  33789 0.32377509405904137 0.10262943822890519