precess

#!/bin/sh
#
# precess - Precess the ra and dec columns from one equinox to another.
#
# Starbase Data Tables  - An Ascii Database for UNIX
#
#   copyright 1991, 1993, 1995, 1999 John B. Roll jr.
#
PATH=.:/bin:/usr/bin;	export PATH

TABLELIB=$TABLELIB;  export TABLELIB
TABLEFUN="";  export TABLEFUN

 while [ $# -ge 1 ] ; do
  case $1 in 
   -o) shift; ifile=$1					;;
   -o) shift; ofile=$1					;;
   -*) echo "preces: unknown option"; exit 1	;;
    *) argv="$argv $1"					;;
  esac
  shift
 done

 if [ "$ifile" != "" ] ; then
	exec < $ifile
 fi

 if [ "$ofile" != "" ] ; then
	exec > $ofile
 fi

table -p $argv '
BEGIN {
	Init = 0

	sys	= "FK4"
	rcol 	= "ra"
	dcol 	= "dec"
	eq0	=  1950
	eq1	=  2000

	paramcheck("preces", "sys|eq0|eq1|rcol|dcol")
}
!Init {	__r = table_colnum(rcol)
	__d = table_colnum(dcol)

	paramrange("preces", "sys", "s", sys, "FK4|fk4|FK5|fk5|FK5nut")

	if ( !__r )	printf("preces: no column \"%s\".\n", rcol)
	if ( !__d )	printf("preces: no column \"%s\".\n", dcol)
	if ( !__r || !__d ) {
		exit 1
	}

	Init = 1
}
{	[ $__r, $__d ] = precess(sys, eq0, eq1, $__r, $__d); print }

include ../tablefun/paramcheck
include ../tablefun/paramrange
include ../tablefun/table_colnum

 '