#include <stdio.h>
#include <string.h>
#include <math.h>
#include <wcslib/cel.h>

// Get a RA and Decl from x and y
void
reverse (double ra0, double de0, double x, double y, double *ra, double *de)
{
  int i, status;
  double phi, theta;
  struct celprm cel;

  x /= 3600.;
  y /= 3600.;

  // Initialize Reference Angles
  celini (&cel);
  cel.ref[0] = ra0;
  cel.ref[1] = de0;
  cel.ref[2] = 999.;
  cel.ref[3] = 999.;
  cel.flag = 0.;
  strcpy (cel.prj.code, "STG");

  if (celset (&cel))
    {
      printf ("Error in Projection (celset)\n");
      return;
    }
  celx2s (&cel, 1, 0, 1, 1, &x, &y, &phi, &theta, ra, de, &status);

  return;
}