CFD Utilities Files

FILTER_LINES description:

   Transcribe any initial non-numeric header lines from a multi-column file
   (if specified, else ignore them) then filter out any further non-numeric
   lines.  Optionally, comment the header line(s) and/or append the same
   line(s) as a trailer.

Controls (namelist on standard input; sample shown):

   $filter
   infile = 'freestream.dat'
   outfile = 'freestream-clean.dat'
   keep_top_header = T
   add_bottom_header = F
   header_comment = '#'
   $end

Notes:

   o  This is for people who don't know awk or similar languages.
   o  Namelist control allows for future extensions without affecting
      existing control files or scripts.
   o  If header_comment = ' ', any header lines are left untouched.
   o  Transcribed numeric lines are copied exactly as is (no reformatting).

History:
   08/21/2014  D.A.Saunders  Initial design, prompted by the need to produce
                             trajectory time histories of high-fidelity flow
                             data, starting with output from NASA ARC's Traj
                             program and selected CFD point results.
                             (Traj repeats its headers every 20 lines, which
                             is inconvenient when pasting a trajectory into
                             a spreadsheet.)
   08/23/2014    "     "     Initial implementation.

Author:  David Saunders, ERC, Inc./NASA Ames Research Center, CA