Description

The analyze_ltcrv.sl script analyzes a lightcurve, e.g. created by dmextract. It performs an iterative sigma-clipping algorithm, removing those points that fall outside +/-3 sigma from the mean at each iteration until all data points are within +/-3 sigma. This algorithm is robust but not perfect; it can easily "overclean" a noisy lightcurve and should not be used blindly. The output is a list of the accepted time periods and their lengths.

The output time periods can then be used to filter the event list, either by using dmgti to create a GTI file, or directly within a DM filter expression.

The script is run from within slsh ("ahelp slsh"), as shown in the example. To load the script:

slsh> () = evalfile("analyze_ltcrv.sl")

This step is only necessary once per slsh session.

This script is used in the Filtering Lightcurves thread.

RUN-TIME ERROR MESSAGES

When analyze_ltcrv.sl prints an error message, the "myerror" routine also prints a S-lang run-time error:

** ERROR **
 analyze_ltcrv() stopped as unable to read data from file

./analyze_ltcrv.sl:63:myerror:Run-Time Error

As long as this is preceded by a script error ("** ERROR **"), it may be ignored. If it does not appear that a script error condition was met, contact the CXC HelpDesk for assistance.