sattools/src/angular.c

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

#define LIM 80

void dec2s (double, char *, int, int);
double s2dec (char *);
void reverse (double, double, double, double, double *, double *);
void forward (double, double, double, double, double *, double *);

int
main (int argc, char *argv[])
{
  int i;
  double ra1, de1, ra2, de2;
  double rx, ry;
  char sra[15], sde[15];

  if (argc == 1)
    {
      printf ("Usage: %s <ra1> <de1> <ra2> <de2>\n", argv[0]);
      printf ("       Computes angular offset\n");
      printf ("Usage: %s -d <ra1> <de1> <dra> <dde>\n", argv[0]);
      printf ("       Applies angular offset\n");
      printf ("Usage: %s -x <ra1> <de1> <ra2> <de2>\n", argv[0]);
      printf ("       Computes x-offset only\n");
      printf ("Usage: %s -y <ra1> <de1> <ra2> <de2>\n", argv[0]);
      printf ("       Computes y-offset only\n");
      return -1;
    }

  if (strcmp (argv[1], "-d") == 0)
    {
      if (strchr (argv[2], ':') != NULL)
	ra1 = 15. * s2dec (argv[2]);
      else
	ra1 = atof (argv[2]);
      if (strchr (argv[3], ':') != NULL)
	de1 = s2dec (argv[3]);
      else
	de1 = atof (argv[3]);

      rx = (double) atof (argv[4]);
      ry = (double) atof (argv[5]);

      reverse (ra1, de1, rx, ry, &ra2, &de2);

      dec2s (ra2 / 15.0, sra, 0, 7);
      dec2s (de2, sde, 0, 6);

      printf ("%s %s\n", sra, sde);
    }
  else if (strcmp (argv[1], "-x") == 0)
    {
      if (strchr (argv[2], ':') != NULL)
	ra1 = 15. * s2dec (argv[2]);
      else
	ra1 = atof (argv[2]);
      if (strchr (argv[3], ':') != NULL)
	de1 = s2dec (argv[3]);
      else
	de1 = atof (argv[3]);
      if (strchr (argv[4], ':') != NULL)
	ra2 = 15. * s2dec (argv[4]);
      else
	ra2 = atof (argv[4]);
      if (strchr (argv[5], ':') != NULL)
	de2 = s2dec (argv[5]);
      else
	de2 = atof (argv[5]);

      forward (ra1, de1, ra2, de2, &rx, &ry);

      printf ("%8.3f\n", rx);
    }
  else if (strcmp (argv[1], "-y") == 0)
    {
      if (strchr (argv[2], ':') != NULL)
	ra1 = 15. * s2dec (argv[2]);
      else
	ra1 = atof (argv[2]);
      if (strchr (argv[3], ':') != NULL)
	de1 = s2dec (argv[3]);
      else
	de1 = atof (argv[3]);
      if (strchr (argv[4], ':') != NULL)
	ra2 = 15. * s2dec (argv[4]);
      else
	ra2 = atof (argv[4]);
      if (strchr (argv[5], ':') != NULL)
	de2 = s2dec (argv[5]);
      else
	de2 = atof (argv[5]);

      forward (ra1, de1, ra2, de2, &rx, &ry);

      printf ("%8.3f\n", ry);
    }
  else
    {
      if (strchr (argv[1], ':') != NULL)
	ra1 = 15. * s2dec (argv[1]);
      else
	ra1 = atof (argv[1]);
      if (strchr (argv[2], ':') != NULL)
	de1 = s2dec (argv[2]);
      else
	de1 = atof (argv[2]);
      if (strchr (argv[3], ':') != NULL)
	ra2 = 15. * s2dec (argv[3]);
      else
	ra2 = atof (argv[3]);
      if (strchr (argv[4], ':') != NULL)
	de2 = s2dec (argv[4]);
      else
	de2 = atof (argv[4]);

      forward (ra1, de1, ra2, de2, &rx, &ry);

      printf ("%8.3f %8.3f %8.3f\n", rx, ry, sqrt (rx * rx + ry * ry));
    }

  return 0;
}

// Convert Decimal into Sexagesimal
void
dec2s (double x, char *s, int f, int len)
{
  int i;
  double sec, deg, min;
  char sign;
  char *form[] = { ":: ", ",, ", "hms", "   " };

  sign = (x < 0 ? '-' : ' ');
  x = 3600. * fabs (x);

  sec = fmod (x, 60.);
  x = (x - sec) / 60.;
  min = fmod (x, 60.);
  x = (x - min) / 60.;
  //  deg=fmod(x,60.);
  deg = x;

  if (len == 7)
    sprintf (s, "%c%02i%c%02i%c%07.4f%c", sign, (int) deg, form[f][0],
	     (int) min, form[f][1], sec, form[f][2]);
  if (len == 6)
    sprintf (s, "%c%02i%c%02i%c%06.3f%c", sign, (int) deg, form[f][0],
	     (int) min, form[f][1], sec, form[f][2]);
  if (len == 5)
    sprintf (s, "%c%02i%c%02i%c%05.2f%c", sign, (int) deg, form[f][0],
	     (int) min, form[f][1], sec, form[f][2]);
  if (len == 4)
    sprintf (s, "%c%02i%c%02i%c%04.1f%c", sign, (int) deg, form[f][0],
	     (int) min, form[f][1], sec, form[f][2]);
  if (len == 2)
    sprintf (s, "%c%02i%c%02i%c%02i%c", sign, (int) deg, form[f][0],
	     (int) min, form[f][1], (int) floor (sec), form[f][2]);

  return;
}

// Convert Sexagesimal into Decimal
double
s2dec (char *s)
{
  double x;
  float deg, min, sec;
  char t[LIM];

  strcpy (t, s);

  deg = fabs (atof (strtok (t, " :")));
  min = fabs (atof (strtok (NULL, " :")));
  sec = fabs (atof (strtok (NULL, " :")));

  x = (double) deg + (double) min / 60. + (double) sec / 3600.;
  if (s[0] == '-')
    x = -x;

  return x;
}