fitswcs.c

/******************************** sextodegde *********************************/
/*
Convert dd dm ds.xxx delta coordinates to degrees.
*/
double  sextodegde(char *dms)
  {
   double	val, sgn;
   char		*str, *ptr;

  str = strtok_r(dms, ": \t", &ptr);
  sgn = (strchr(str, '-') ? -1.0:1.0);
  val = atof(dms);					/* Degrees */
  val += atof(strtok_r(NULL, ": \t", &ptr))*sgn/60.0;	/* Minutes */
  val += atof(strtok_r(NULL, ": \t", &ptr))*sgn/3600.0;	/* Seconds */

  return val;
  }


/******************************** fmod_0_p360 *******************************/
/*
Fold input angle in the [0,+360[ domain.
*/
double  fmod_0_p360(double angle)
  {
  return angle>0.0? fmod(angle,360.0) : fmod(angle,360.0)+360.0;
  }


/******************************** fmod_m90_p90 *******************************/
/*
Fold input angle in the [-90,+90[ domain.
*/
double  fmod_m90_p90(double angle)
  {
  return angle>0.0? fmod(angle+90.0,180.0)-90.0 : fmod(angle-90.0,180.0)+90.0;
  }


/********************************* fcmp_0_p360 *******************************/
/*
Compare angles in the [0,+360[ domain: return 1 if anglep>anglem, 0 otherwise.
*/
int  fcmp_0_p360(double anglep, double anglem)
  {
   double dval = anglep - anglem;

  return (int)((dval>0.0 && dval<180.0) || dval<-180.0);
  }