fcatdiff - This task compares specified columns of a fits file, and reports those that differ from row to row.


        fcatdiff infile outfile keywords


The task takes the columns listed in the parameter keywords in the file outfile, and writes a new row into the file outfile each time the value in one of these columns changes between two adjoining rows. It writes out the column name and type, and the old value, and the new value. The latter two are written out as ascii strings. If none of the keyword column values have changed, then it writes 'NONE' in the parameter column, and 'NA' in the value columns. It will also copy over other of the columns in the input file, if they are listed in the parameter copyover.


infile [filename]
The file name and extension number in square brackets of the input table.

outfile [filename]
The name of the output FITS table. If preceeded by a !, and existing file of the same name will be overwritten.

keywords [string]
A list of the columns in the input file whose differences are to be reported. A '-' means to use all the keywords not listed in the copyover and exclude parameter lists. If the first character of the string is '@', the rest of the string is taken to be a filename containing the column names, one per line.

(copyover = " ") [string]
A list of the columns to be copied over from infile to outfile. The '@' sign has the same meaning as for keywords.

(exclude = " ") [string]
A list of columns to be excluded from the keywords list if that has the value '-'. The '@' sign has the same meaning as for keywords.

(clobber = no) [boolean]
If true, a file with the same name as the requested output file will be overwritten.


1. Record the differences in the columns BIT_RATE and MODE in the file cat.fits, copying over the columns TSTART and TSTOP.

           ft> fcatdiff cat.fits out.fits "BIT_RATE MODE" copyover = "TSTART TSTOP"




June92 ftools.futils