From 06680af02445218bd54f5df0df0013149b8a674c Mon Sep 17 00:00:00 2001
From: Bill-Gray <pluto@projectpluto.com>
Date: Sun, 3 Dec 2023 16:09:28 -0500
Subject: [PATCH] Added get_ra_dec_from_string() and get_dec_from_string()
 functions.  To be used initially in the satellites-in-field-finding program, 
 but they should be used anywhere RA or dec strings are input and parsed.

---
 mpc_code.cpp | 39 ++++++++++++++++++++++++++++++++++++++-
 mpc_func.h   |  2 ++
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/mpc_code.cpp b/mpc_code.cpp
index f41fb74..0ebeb8a 100644
--- a/mpc_code.cpp
+++ b/mpc_code.cpp
@@ -446,8 +446,11 @@ static double _get_angle( const char *buff, int *nbytes, int *n_fields)
 {
    double rval;
    const char *tptr = buff;
-   int is_integer;
+   int is_integer, dummy_nbytes;
 
+   assert( n_fields);
+   if( !nbytes)
+      nbytes = &dummy_nbytes;
    *n_fields = 0;
    rval = _get_number_for_angle( buff, nbytes, &is_integer);
    if( is_integer != -1)
@@ -645,6 +648,40 @@ int get_lat_lon_info( mpc_code_t *cinfo, const char *buff)
    return( rval);
 }
 
+double get_ra_from_string( const char *buff, int *bytes_read)
+{
+   int n_fields;
+   double rval = _get_angle( buff, bytes_read, &n_fields);
+
+   if( n_fields > 2)     /* assume HH MM.mm or HH MM SS.sss */
+      rval *= 15.;
+   if( !n_fields || rval > 360.)
+      *bytes_read = 0;
+   return( rval * PI / 180.);
+}
+
+double get_dec_from_string( const char *buff, int *bytes_read)
+{
+   if( *buff != '+' && *buff != '-')
+      {
+      *bytes_read = 0;
+      return( 0.);
+      }
+   else
+      {
+      int n_fields;
+      double rval = _get_angle( buff + 1, bytes_read, &n_fields);
+
+      if( !n_fields || rval > 90.)
+         *bytes_read = 0;
+      if( *buff == '-')
+         rval = -rval;
+      if( n_fields)
+         (*bytes_read)++;
+      return( rval * PI / 180.);
+      }
+}
+
 /* https://www.minorplanetcenter.net/iau/info/Astrometry.html#HowObsCode
 suggests that you start out using "observatory code" (XXX),  whilst
 including a comment such as
diff --git a/mpc_func.h b/mpc_func.h
index 1c02709..d6a1958 100644
--- a/mpc_func.h
+++ b/mpc_func.h
@@ -50,6 +50,8 @@ typedef struct
 int get_mpc_code_info( mpc_code_t *cinfo, const char *buff);
 int get_xxx_location_info( mpc_code_t *cinfo, const char *buff);
 int get_lat_lon_info( mpc_code_t *cinfo, const char *buff);
+double get_ra_from_string( const char *buff, int *bytes_read);
+double get_dec_from_string( const char *buff, int *bytes_read);
 double point_to_ellipse( const double a, const double b,
                          const double x, const double y, double *dist);
 int lat_alt_to_parallax( const double lat, const double ht_in_meters,