anchor.diff:     subroutine usage()
      !===============================================================================
         write(0,'(a)') &
  -         'Usage: lonlat2xyz (options) < [lon] [lat] [radius]', &
  +         'Usage: lonlat2xyz (options) < [lon] [lat] [radius] (value)', &
            'Reads geographic coordinates from stdin and writes cartesian to stdout.', &
            'Options:', &
  +         '   -v          : Output the value in the third/fourth column', &
            '   -r [radius] : Fix radius.  If not present, r must be on stdin.'
         stop 1
      end subroutine usage
  
positive.code:    iostat = 0
     do while (iostat == 0)
        if (fixed_rad) then
           read(*,*,iostat=iostat) lon, lat
        else
           read(*,*,iostat=iostat) lon, lat, r
        endif
        if (iostat < 0) exit
        if (iostat > 0) then
  
negative.code:                endif
                 fixed_rad = .true.
                 iarg = iarg + 2
              case('-v')
                 value = .true.
                 iarg = iarg + 1
              case('-h')
                 call usage
              case default
  