MGTIME (October 1998)          ftools.time         MGTIME (October 1998)



NAME
    mgtime -- Merge two or more GTI FITS files.
    
    
USAGE
    mgtime ingtis outgti
    
    
DESCRIPTION
    This  task  merges two or more (up to 400) Good Time Interval files,
    using either of two modes:
       AND - output GTI file contains time intervals common to both files,
       OR  - output GTI file combines time intervals from both files.
    
    
PARAMETERS
    
    ingtis [filenames]
        The file names and extensions for input GTI  FITS  files  to  be
        merged.   Optionally  the list of file names can be placed in an
        ASCII file, one name per line, and then the name  of  the  file,
        proceeded  by  an  "@"  character  may  be given to the "ingtis"
        parameter.  Empty input GTI lists are ignored with  a  warning--
        they do *not* indicate the lack of any good time at all.
    
    outgti [filename]
        The file name for merged output GTI FITS file.
    
    merge [string]
        The merge mode, either logical "AND" or logical "OR".
    
    (instarts = "START") [string]
        Names  of columns for start times in input files, up to 400.  If
        the values are different in  the  different  files,  supply  one
        column name for each file.  Times are assumed to be in seconds.
    
    (instops = "STOP") [string]
        Names  of  columns for stop times in input files, up to 400.  If
        the values are different in  the  different  files,  supply  one
        column name for each file.  Times are assumed to be in seconds.
    
    (indates = "MJDREF") [string]
        Names  of  keywords for reference date of the times in the input
        files, up to 400.  If the values are different in the  different
        files,  supply  one  column name for each file.  Three reference
        time formats are supported: the reference zero time  may  be  in
        julian  days,  in  yyyy-mm-dd format, or in dd/mm/yy (19yy only)
        format.  If no reference time checking is desired,  a  blank  or
        "-" may be entered.
    
    (intimes = " ") [string]
        Names  of  keywords  for the reference start time of the time in
        input files, up to 400.  If the  values  are  different  in  the
        different  files,  supply  one  column name for each file.  This
        value is  only  used  for  indates  in  yyyy-mm-dd  or  dd/mm/yy
        format.  The format of this keyword is hh:mm:ss.sss.
    
    (outstart = "START") [string]
        Name  of  column  for  start  times  in  output file.  Times are
        output in seconds.
    
    (outstop = "STOP") [string]
        Name of column for stop times.  Times are output in seconds.
    
    
EXAMPLES
    1.  Merge by logical ANDing contents of the two GTI FITS files,
        gti1.fits and gti2.fits into the output GTI FITS file gtiout.fits
        using defaults for all other hidden parameters:
    
            ft> mgtime "gti1.fits,gti2.fits" gtiout.fits AND
    
    2.  Merge by logical ORing contents of the two GTI FITS files,
        gti1.fits[3] and gti2.fits[2] into the output GTI FITS file
        gtiout.fits:
    
            ft> mgtime "gti1.fits[3],gti2.fits[2]" gtiout.fits OR
    
    
NOTE
    It can be argued (and has been!) that empty input GTI  lists  should
    be  significant,  indicating  no good time.  However, it was decided
    long ago that such GTI files are invalid and should be ignored,  and
    this  is  for the most part standard behavior among the ftools.  (In
    mgtime, obviously this only affects merge=AND.)
    
    
BUGS
    
    
SEE ALSO
    maketime