Instrument Response Functions (irf)

This module contains functionalities for generating instrument response functions. The simulated events used for this have to be selected based on their associated “gammaness” value and (optionally) their reconstructed angular offset from their point of origin. The code for doing this can found in G/H (and Theta) Cut Optimization and is intended for use via the EventSelectionOptimizer tool.

The generation of the irf components themselves is implemented in IRF components and is intended for use via the IrfTool tool. This tool can optionally also compute some common benchmarks, which are implemented in Benchmarks.

The cut optimization as well as the calculations of the irf components and the benchmarks are done using the pyirf package.

Binning, Event Loading and Preprocessing, and Spectra definitions for event weights contain helper functions and classes used by many of the other components in this module.

Submodules

• G/H (and Theta) Cut Optimization
• IRF components
• Benchmarks
• Binning
• Event Loading and Preprocessing
• Spectra definitions for event weights

Reference/API

ctapipe.irf Package

Top level module for the irf functionality

Functions

check_bins_in_range(bins, valid_range[, ...])	Check whether bins are within a valid_range and either warn or raise an error if not.
make_bins_per_decade(e_min, e_max[, ...])	Create energy bins with at least n_bins_per_decade bins per decade, while using the exact lower (e_min) and upper (e_max) limits.

Classes

AngularResolution2dMaker(**kwargs)	Calculates the angular resolution in bins of either true or reconstructed energy and fov offset.
EnergyBiasResolution2dMaker(**kwargs)	Calculates the bias and the resolution of the energy prediction in bins of true energy and fov offset.
Sensitivity2dMaker(**kwargs)	Calculates the point source sensitivity in bins of reconstructed energy and fov offset.
PSF3DMaker(**kwargs)	Creates a radially symmetric point spread function calculated in equidistant bins of source offset, logarithmic true energy, and field of view offset.
BackgroundRate2dMaker(**kwargs)	Creates a radially symmetric parameterization of the background rate in equidistant bins of logarithmic reconstructed energy and field of view offset.
EnergyDispersion2dMaker(**kwargs)	Creates a radially symmetric parameterization of the energy dispersion in equidistant bins of logarithmic true energy and field of view offset.
EffectiveArea2dMaker(**kwargs)	Creates a radially symmetric parameterization of the effective area in equidistant bins of logarithmic true energy and field of view offset.
ResultValidRange(min, max)
OptimizationResult(valid_energy_min, ...[, ...])	Result of an optimization of G/H and theta cuts or only G/H cuts.
PointSourceSensitivityOptimizer(**kwargs)	Optimizes a G/H cut for maximum point source sensitivity and calculates a percentile cut on theta.
PercentileCuts(**kwargs)	Calculates G/H separation cut based on the percentile of signal events to keep in each bin.
EventLoader(**kwargs)	Contains functions to load events and simulation information from a file and derive some additional columns needed for irf calculation.
EventPreprocessor(**kwargs)	Defines pre-selection cuts and the necessary renaming of columns.
Spectra(value)	Spectra for calculating event weights
GhPercentileCutCalculator(**kwargs)	Computes a percentile cut on gammaness.
ThetaPercentileCutCalculator(**kwargs)	Computes a percentile cut on theta.