NAME:
  wrphot
 PURPOSE: (one line)
  Write a standard raw photometry data file (Pluto format).
 DESCRIPTION:
  This creates a .001 format Pluto-Charon format file from the input
    photometry.  As a suggestion, use .000 as a suffix if these are NOT
    standard magnitudes (such as differential to some star), and use
    .001 if they are magnitudes on a standard system.

      File format: (one blank separates each field)

         Orbit Flag . . . . . . . . . . I1      1 -> Search for new orbital
                                                     elements that most
            This is a flag to the program            closely match the time
            PLEPH that controls which set            of observation.
            of orbital elements to use          0 -> Use the same set of
            for the Pluto ephemeris.                 orbital elements as used
                                                     for the previous point.
        This is always set to zero in the output from this program.

         JD of observation (UT) . . . . F13.5   Julian date of the observation.

         Filter ID  . . . . . . . . . . A2      Two character id of the filter
                                                used for the observation.
                                                Consult the filter documentation
                                                to get the ID's that are
                                                currently in use.
        Only the first two characters of the filter field are saved to the file.

         Observed Magnitude . . . . . . F7.4    Observed magnitude reduced to
                                                some standard system.  The
                                                filter ID must reflect this
                                                system.

         Uncertainty (sigma)  . . . . . F6.4    Error bar for observation.

         Source . . . . . . . . . . . . A45     Free format field to reference
                                                the observer and the telescope
                                                used for the observation.
        This is left blank by this program.

 CATEGORY:
  File I/O
 CALLING SEQUENCE:
  wrphot,jd,filter,mag,err,file
 INPUTS:
  jd     - Julian date of observation (double precision).
  filter - String array of filter names.
  mag    - Observed magnitude.
  err    - Uncertainty on the observed magnitude.
  file   - String with name of file to save photometry to.
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
  APPEND - if set appends data to the named file.
  BAD    - if supplied, must be a vector of flags, 0=good, 1=bad
 OUTPUTS:
 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  Written by Marc W. Buie, Lowell Observatory, 1993 Jun 26
  96/11/03, MWB, added BAD input
  2006/08/10, Peter L. Collins, Lowell Observatory, added SELF and
              fixed small bug where nfil unchecked if not 1.