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/*
*
* twcs.c -- example using WCS Library
*
*/
#include <funtools.h>
int main(int argc, char **argv)
{
int i;
Fun fun;
struct WorldCoor *wcs; /* WCS info */
double x,y,ra,dec,xr,yr;
if(argc == 1){
fprintf(stderr, "usage: twcs iname\n");
exit(1);
}
/* open Funtools file */
/* Funopen makes initial WCS library call: wcs = wcsinit(header_string) */
if( !(fun = FunOpen(argv[1], "r ", NULL)) ){
fprintf(stderr, "ERROR can't open file: %s\n", argv[1]);
exit(1);
}
/* get wcs structure */
FunInfoGet(fun,FUN_WCS,&wcs,0);
if( !wcs || !iswcs(wcs) ){
fprintf(stderr,"No WCS data");
return(1);
}
/* read input, convert pixels to wcs and back */
while(1){
fprintf(stdout,"\nInput x y: ");
if(scanf("%lf %lf", &x, &y) != EOF){
if(x <= -999)
break;
/* convert image pixels to sky coords */
pix2wcs(wcs, x, y, &ra, &dec);
fprintf(stdout,"Convert from pixels to ra,dec using pix2wcs()\n");
fprintf(stdout, "x=%.10g y=%.10g -> ra=%.10g dec=%.10g\n",
x, y, ra, dec);
/* convert sky coords to image pixels */
fprintf(stdout,"Convert from ra,dec -> pixels using wcs2pix()\n");
wcs2pix(wcs, ra, dec, &xr, &yr, &i);
fprintf(stdout, "ra=%.10g dec=%.10g -> x=%.10g y=%.10g offscale=%d\n",
ra, dec, xr, yr, i);
}
else
break;
}
/* clean up */
/* FunClose makes final WCS library call: wcsfree(wcs) */
FunClose(fun);
return(0);
}
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