cstsdist
Generates the TS distribution for a given source.
Synopsis
This script generates the Test Statistics (TS) distribution for a given source by repeatedly computing the TS value for ntrials simulated data sets. The Test Statistics is defined as twice the log-likelihood difference that is obtained when fitting simulated data with and without a given source model component.
cstsdist will create an ASCII file in comma-separated value (CSV) format, containing one row per TS computation. The first row is a header row providing the column names. The following rows give the TS value, the log-likelihood values of the fit with or without the source, the number of observed and fitted events, as well as the values and errors for all fitted parameters.
From the output file, TS distribution plots can be generated using for example the show_ts_distribution.py script in the examples folder. The script requires matplotlib for plotting.
Warning
This script does not work for On/Off observations. If an observation definition XML file is specified the script assumes that all observations are event lists.
General parameters
- inobs [file]
- Input event list, counts cube or observation definition XML file.
- inmodel [file]
- Input model XML file.
- srcname [string]
- Name of the source in the source model XML file which should be used for Test Statistics computation.
- expcube [file]
- Input exposure cube file.
- psfcube [file]
- Input PSF cube file.
- edispcube [file]
- Input energy dispersion cube file.
- bkgcube [file]
- Input background cube file.
- caldb [string]
- Calibration database.
- irf [string]
- Instrumental response function.
- (edisp = no) [boolean]
- Apply energy dispersion to response computation.
- (deadc = 0.98) [real]
- Average deadtime correction factor.
- outfile [file]
- Output ASCII file containing the TS distribution values.
- ntrials [integer]
- Number of Monte Carlo samples.
- (statistic = DEFAULT) <DEFAULT|CSTAT|WSTAT|CHI2> [string]
- Optimization statistic. DEFAULT uses the default statistic for all observations, which is CSTAT or the statistic specified in the observation definition XML file. CSTAT uses the C statistic for all observations, WSTAT uses the W statistic for all On/Off observations, and CHI2 uses the Chi squared statistic for all binned or stacked observations.
Standard parameters
- (chatter = 2) [integer]
- Verbosity of the executable:
chatter = 0: no information will be logged
chatter = 1: only errors will be logged
chatter = 2: errors and actions will be logged
chatter = 3: report about the task execution
chatter = 4: detailed report about the task execution
- (clobber = yes) [boolean]
- Specifies whether an existing output file should be overwritten.
- (debug = no) [boolean]
- Enables debug mode. In debug mode the executable will dump any log file output to the console.
- (mode = ql) [string]
- Mode of automatic parameters (default is ql, i.e. "query and learn").
- (logfile = cstsdist.log) [string]
- Log filename.