NAME

gcorpha -- remaps PHA channels from SPECTRUM extension.


USAGE

gcorpha infil shftfil outfil


DESCRIPTION

This task remaps PHA channels according as defined by user.

Given an OGIP-approved FITS format input file, this task provides the facility to move the user-defined PHA channel elements (columns) of the array to the left or right (ie down or up in channel-space) by a user-defined number of channels.

The shift to be applied to each channel of the input PHA channels must be specified by an ASCII input file. The format of each row of this input ASCII file must be

MINCHAN MAXCHAN NCHAN

denoting all 'columns' of the i/p PHA channels between detector channels MINCHAN and MAXCHAN (inclusive) are to be shifted by NCHAN. The shift, NCHAN, can be a positive or negative INTEGER or real number of channels (or zero). Any channel ranges "implied" by their exclusion from the ASCII file will be shifted by zero channels. Note that should the shift applied to two or more 'columns' result in those columns being in the same o/p detector channel, then their respective probabilities (that an incident photon of a given energy will be detected in that detector channel) WILL BE SUMMED. Similarly, should the applied shifts result in an o/p detector channel 'column' NOT being populated, then the probability (that an incident photon of a given energy will be detected in that detector channel) will be set to zero. However, shifts below the minimum, and above the maximum legal channel number for the instrument will result in those probabilities being excluded.


WARNINGS ON USAGE


PARAMETERS

infil [character string]
The name of the FITS PHA file to be remapped in channel-space

outfil [character string]
The name of the FITS file to be written containing the remapped PHA dataset

shftfil [character string]
The name of an ascii file specifying the remapping information. The ascii file format should be of the form :

1 20 -1
21 30 0

where channels 1 to 20 are shifted back by one, and 21 to 30 stay as they are.

(chatter = 9) [integer]
Flag to indicate how chatty the task is at execution. A value of 9 is the default, with lower/higher values producing quieter/verbose output respectively.

(clobber = false) [boolean]
Flag specifying whether or not a pre-existing file with the same name as that requested as the output file from this task will be overwritten.


BUGS

None known


SEE ALSO

GCORRMF


LOG OF SIGNIFICANT CHANGES

v1.0.0 (1996 June)
Initial public release


PRIMARY AUTHOR

Banashree Mitra Seifert

HEASARC

NASA/GFSC

http://heasarc.gsfc.nasa.gov/cgi-bin/ftoolshelp

(301) 286-5307

CATEGORY

May96 ftools.caltools