# Gather Summary Statistics (ligo-skymap-stats)¶

Calculate summary statistics for a batch of sky maps.

Under the hood, this script is little more than a command-line interface for the ligo.skymap.postprocess.crossmatch module.

The filenames of the sky maps may be provided as positional command line arguments, and may also be provided as globs (such as *.fits.gz). If supplied with the optional --database argument, then also match sky maps with injections from an inspinjfind-style sqlite database.

All angular separations are in degrees, all areas are in square degrees, and all volumes are in cubic megaparsecs. The output is written as tab-separated values with the following columns:

 From the search pipeline database coinc_event_id event identifier simulation_id injection identifier far false alarm rate snr signal to noise ratio Injection finding searched_area area of 2D credible region containing the true sky location searched_prob probability in that 2D credible region searched_prob_dist marginal distance CDF at the true distance searched_vol volume of 3D credible region containing the true position searched_prob_vol probability contained in that volume offset angular separation between the maximum a posteriori position and the true sky position Additional metadata from the sky maps runtime wall clock run time to generate sky map distmean mean a posteriori distance diststd a posteriori standard deviation of distance log_bci natural log Bayes factor, coherent vs. incoherent log_bsn natural log Bayes factor, signal vs. noise Credible levels (if --area or --contour options present) area(P) area of the P percent 2D credible region prob(A) probability contained within the 2D credible level of area A dist(P) distance for a cumulative marginal probability of P percent vol(P) volume of the P percent 3D credible region Modes (if --modes option is present) searched_modes number of simply connected figures in the 2D credible region containing the true sky location modes(P) number of simply connected figures in the P percent 2D credible region

usage: ligo-skymap-stats [-h] [--version]
[-l CRITICAL|ERROR|WARNING|INFO|DEBUG|NOTSET]
[-o OUT.dat] [-j [JOBS]] [-p PERCENT [PERCENT ...]]
[-a DEG2 [DEG2 ...]] [--modes] [-d DB.sqlite]
[--cosmology]
GLOB.fits[.gz] [GLOB.fits[.gz] ...]


## Positional Arguments¶

GLOB.fits[.gz]

Input FITS filenames and/or globs

## Named Arguments¶

--version

show program’s version number and exit

-l, --loglevel

Default: INFO

-o, --output

Name of output file

Default: -

-j, --jobs

Default: 1

-p, --contour

Report the area of the smallest contour and the number of modes containing this much probability.

Default: []

-a, --area

Report the largest probability contained within any region of this area in square degrees. Can be repeated multiple times.

Default: []

--modes

Compute number of disjoint modes

Default: False

-d, --database

Input SQLite database from search pipeline

--cosmology

Report volume localizations as comoving volumes.

Default: False