Source code for gammapy.data.gti

# Licensed under a 3-clause BSD style license - see LICENSE.rst
from __future__ import absolute_import, division, print_function, unicode_literals
from astropy.units import Quantity
from astropy.table import Table
from ..utils.time import time_ref_from_dict
from ..utils.scripts import make_path

__all__ = ["GTI"]


[docs]class GTI(object): """Good time intervals (GTI) `~astropy.table.Table`. Data format specification: :ref:`gadf:iact-gti` Note: at the moment dead-time and live-time is in the EVENTS header ... the GTI header just deals with observation times. Parameters ---------- table : `~astropy.table.Table` GTI table Examples -------- Load GTIs for a H.E.S.S. event list: >>> from gammapy.data import GTI >>> gti = GTI.read('$GAMMAPY_DATA/hess-dl3-dr1//data/hess_dl3_dr1_obs_id_023523.fits.gz') >>> print(gti) GTI info: - Number of GTIs: 1 - Duration: 1687.0 s - Start: 53343.92234009259 MET - Start: 2004-12-04T22:08:10.184(TT) - Stop: 53343.94186555556 MET - Stop: 2004-12-04T22:36:17.184(TT) Load GTIs for a Fermi-LAT event list: >>> gti = GTI.read('$GAMMAPY_DATA/fermi_2fhl/2fhl_events.fits.gz') >>> print(gti) GTI info: - Number of GTIs: 36589 - Duration: 171273490.97510204 s - Start: 54682.659499814814 MET - Start: 2008-08-04T15:49:40.784(TT) - Stop: 57053.99355074074 MET - Stop: 2015-01-31T23:50:42.784(TT) """ def __init__(self, table): self.table = table
[docs] @classmethod def read(cls, filename, **kwargs): """Read from FITS file. Parameters ---------- filename : `~gammapy.extern.pathlib.Path`, str Filename """ filename = make_path(filename) kwargs.setdefault("hdu", "GTI") table = Table.read(str(filename), **kwargs) return cls(table=table)
def __str__(self): ss = "GTI info:\n" ss += "- Number of GTIs: {}\n".format(len(self.table)) ss += "- Duration: {}\n".format(self.time_sum) ss += "- Start: {} MET\n".format(self.time_start[0]) ss += "- Start: {}\n".format(self.time_start[0].fits) ss += "- Stop: {} MET\n".format(self.time_stop[-1]) ss += "- Stop: {}\n".format(self.time_stop[-1].fits) return ss @property def time_delta(self): """GTI durations in seconds (`~astropy.units.Quantity`).""" start = self.table["START"].astype("float64") stop = self.table["STOP"].astype("float64") return Quantity(stop - start, "second") @property def time_sum(self): """Sum of GTIs in seconds (`~astropy.units.Quantity`).""" return self.time_delta.sum() @property def time_start(self): """GTI start times (`~astropy.time.Time`).""" met_ref = time_ref_from_dict(self.table.meta) met = Quantity(self.table["START"].astype("float64"), "second") return met_ref + met @property def time_stop(self): """GTI end times (`~astropy.time.Time`).""" met_ref = time_ref_from_dict(self.table.meta) met = Quantity(self.table["STOP"].astype("float64"), "second") return met_ref + met