Correcting error of julian day calculations, make functions more C like

src/calculations.c

@@ -11,46 +11,48 @@ float calc_rad_deg (float rad) {
 
 
 /* Get current time and date and return as a pointer to an array */
-int *calc_time_utc ()
+void calc_time_utc (int *time_utc)
 {
   time_t t;
   struct tm *tmp;
-  int *time_utc;
 
   t = time(NULL);
   tmp = gmtime(&t);
 
   g_print ("UTC: %02d:%02d:%02d - %d.%d.%d\n", tmp->tm_hour, tmp->tm_min, tmp->tm_sec, tmp->tm_mday, tmp->tm_mon+1, tmp->tm_year+1900);
 
-  int time_utc_array[6] = {tmp->tm_year+1900, tmp->tm_mon+1, tmp->tm_mday, tmp->tm_hour, tmp->tm_min, tmp->tm_sec};
-  time_utc = time_utc_array;
-  return time_utc;
+  *(time_utc) = tmp->tm_year+1900;
+  *(time_utc+1) = tmp->tm_mon+1;
+  *(time_utc+2) = tmp->tm_mday;
+  *(time_utc+3) = tmp->tm_hour;
+  *(time_utc+4) = tmp->tm_min;
+  *(time_utc+5) = tmp->tm_sec;
 }
 
 
 /* Calculate the Julian Day */
-double calc_jd (int *time_utc)
+void calc_jd (int *time_utc, double *time_jd)
 {
-  int year = *time_utc;
-  int month = *(time_utc+1);
-  float day = *(time_utc+2);
-  int hour = *(time_utc+3);
-  int min = *(time_utc+4);
-  int sec = *(time_utc+5);
+  float year = *time_utc;
+  float month = *(time_utc+1);
+  double day = *(time_utc+2);
+  float hour = *(time_utc+3);
+  float min = *(time_utc+4);
+  float sec = *(time_utc+5);
 
+  g_print ("Seconds: %f, Minute: %f, Hour: %f, Day: %f, Month: %f, Year: %f\n",sec,min,hour,day,month,year);
   /* calculate a float type day number which is direct proportional to the time went by */
-  day += hour/24 + min/60 + sec/3600;
+  day += (hour + (min + sec/60.)/60.)/24.;
 
-  g_print ("Day: %02f, Month: %02d, Year:%02d",day,month,year);
-
-  double jd;
+  g_print ("Day: %f, Month: %f, Year:%f\n",day,month,year);
 
   if (month<=2){
     year --;
     month += 12;
   }
-  jd = (int)(365.25*(year+4716)) + (int)(30.6001*(month+1)) + day + 2 - (int)(year/100) + (int)(year/400) - 1524.5;
-  g_print ("Julian Day: %f\n",jd);
+
+  *time_jd = (int)(365.25*(year+4716.)) + (int)(30.6001*(month+1.)) - (int)(year/100.) + (int)(year/400.) + day + 2. - 1524.5;
+  g_print ("Julian Day: %f\n",*time_jd);
 
   /*Explanation:
    * There are 5 main parts in this calculation.
@@ -83,7 +85,6 @@ double calc_jd (int *time_utc)
    *
    * --> combining all of this leads to the above formula.
    */
-  return jd;
 }
 
 

src/calculations.h

@@ -6,9 +6,9 @@ float calc_deg_rad (float deg);
 
 float calc_rad_deg (float rad);
 
-int *calc_time_utc ();
+void calc_time_utc (int *time_utc);
 
-double calc_jd (int *time_utc);
+void calc_jd (int *time_utc, double *time_jd);
 
 double calc_sidereal_time(float longitude, double time_jd);
 

src/handler.c

@@ -2,12 +2,13 @@
 
 float *hand_milky_way(float latitude, float longitude, int *time_utc){
 
+  double time_jd;
   float right_ascension = 266.5;
   float declination = -29.00;
-  g_print("Handler Milky Way\n");
+  g_print("Handler Milky Way, Year: %d\n", *time_utc);
   /* translate time to JD */
 
-  double time_jd = calc_jd(time_utc);
+  calc_jd(time_utc, &time_jd);
 
   /* calculate siderial time */
 

src/handler.h

@@ -1,4 +1,4 @@
 #include <gtk/gtk.h>
 #include <calculations.h>
 
-float *hand_milky_way(float latitude, float longitude, int *time);
+float *hand_milky_way(float latitude, float longitude, int *time_utc);

src/main.c

@@ -89,8 +89,9 @@ static int calculate (GtkWidget *widget, gpointer data)
   float longitude = atof(gtk_entry_get_text (east_entry));
   g_print("Calculation ongoing\n");
 
-  int *time_utc_now = calc_time_utc ();
-  hand_milky_way (latitude, longitude, time_utc_now);
+  int time_utc_now[6];
+  calc_time_utc (&time_utc_now[0]);
+  hand_milky_way (latitude, longitude, &time_utc_now[0]);
   return 1;
 }
 static gboolean delete_event(GtkWidget *widget, GdkEvent *event, gpointer data)