findex -- Create an index for a particular column in a FITS table or bintable extension.
findex filename[ext#] outfile column
This task is used to create an index FITS file on a specified column in the input FITS file. This index file may then be used as input to some of the other ftools tasks to speed up the processing time.
1. Create an index for the column named MyColumn in the second extension of the FITS file test.fits and write the indexing information to the FITS file testx.fits.
ft> findex test.fits MyColumn testx.fits
flcol, ftabcopy, fselect