# Licensed under a 3-clause BSD style license - see LICENSE.rst
import numpy as np
from gammapy.data import EventList
from gammapy.datasets import SpectrumDatasetOnOff
from gammapy.maps import RegionNDMap
__all__ = ["PhaseBackgroundMaker"]
[docs]class PhaseBackgroundMaker:
"""Background estimation with on and off phases.
TODO: For a usage example see future notebook.
TODO: The phase interval has to be between 0 and 1.
Cases like [-0.1, 0.1], for example, are still not supported.
Parameters
----------
on_phase : `tuple` or list of tuples
on-phase defined by the two edges of each interval (edges are excluded)
off_phase : `tuple` or list of tuples
off-phase defined by the two edges of each interval (edges are excluded)
"""
def __init__(self, on_phase, off_phase):
self.on_phase = self._check_intervals(on_phase)
self.off_phase = self._check_intervals(off_phase)
def __str__(self):
s = self.__class__.__name__
s += f"\n{self.on_phase}"
s += f"\n{self.off_phase}"
return s
@staticmethod
def _make_counts(dataset, observation, phases):
event_lists = []
for interval in phases:
events = observation.events.select_parameter(
parameter="PHASE", band=interval
)
event_lists.append(events)
events = EventList.stack(event_lists)
counts = RegionNDMap.from_geom(dataset.counts.geom)
counts.fill_events(events)
return counts
[docs] def make_counts_off(self, dataset, observation):
"""Make off counts.
Parameters
----------
dataset : `SpectrumDataset`
Input dataset.
observation : `DatastoreObservation`
Data store observation.
Returns
-------
counts_off : `RegionNDMap`
Off counts.
"""
return self._make_counts(dataset, observation, self.off_phase)
[docs] def make_counts(self, dataset, observation):
"""Make off counts.
Parameters
----------
dataset : `SpectrumDataset`
Input dataset.
observation : `DatastoreObservation`
Data store observation.
Returns
-------
counts_off : `RegionNDMap`
Off counts.
"""
return self._make_counts(dataset, observation, self.on_phase)
[docs] def run(self, dataset, observation):
"""Run all steps.
Parameters
----------
dataset : `SpectrumDataset`
Input dataset.
observation : `Observation`
Data store observation.
Returns
-------
dataset_on_off : `SpectrumDatasetOnOff`
On off dataset.
"""
counts_off = self.make_counts_off(dataset, observation)
counts = self.make_counts(dataset, observation)
acceptance = np.sum([_[1] - _[0] for _ in self.on_phase])
acceptance_off = np.sum([_[1] - _[0] for _ in self.off_phase])
dataset_on_off = SpectrumDatasetOnOff.from_spectrum_dataset(
dataset=dataset,
counts_off=counts_off,
acceptance=acceptance,
acceptance_off=acceptance_off,
)
dataset_on_off.counts = counts
return dataset_on_off
@staticmethod
def _check_intervals(intervals):
"""Split phase intervals that go beyond phase 1"""
if isinstance(intervals, tuple):
intervals = [intervals]
for phase_interval in intervals:
if phase_interval[0] > phase_interval[1]:
intervals.remove(phase_interval)
intervals.append([phase_interval[0], 1])
intervals.append([0, phase_interval[1]])
return intervals