distance and bearing with PIC

[zahidkhan]

what is the efficient method of computing distance and bearing between two latitudes and longitudes using PIC 16F877 or 18F452.Using trig function consumes all rom.
any suggestions ?

 

[newelltech]

How do a few trig functions consume all of ROM?
How much ROM do you have?
Post your calculations, because it shouldn't be that math intensive.

 

[zahidkhan]

How do a few trig functions consume all of ROM?
How much ROM do you have?
Post your calculations, because it shouldn't be that math intensive.[/quot]
with 16f877A ROM usage for gps parsing is about 35% but including the following code ,ROM usage jumps to more than 80%. and yet goal is not achieved as calculations are not accurate.

#include<math.h>
#include<stdio.h>
#define PI 3.141592654
#define EARTH 6371
void dist();
void dist()
{


   float lat1,lat2,dlat,long1,long2,dlong,tmp1,tmp2,tmp3,tmp4,d,bearing;
   lat1=31.000000*PI/180;
   lat2=31.600000*PI/180;
   long1=74.002000*PI/180;
   long2=74.000000*PI/180;
   dlat=lat1-lat2;
   dlong=long1-long2;
   //tmp1=(sin(dlat/2)*sin(dlat/2))+cos(lat1)*cos(lat2)*(sin(dlong/2)*sin(dlong/2));
   //tmp2=2*atan2(sqrt(tmp1),sqrt(1-tmp1));
   //d=EARTH*tmp2;

   //d=acos(sin(lat1)*sin(lat2)+cos(lat1)*cos(lat2)*cos(long2-long1))*EARTH;
   //bearing=atan2(sin(dlong).cos(lat2),cos(lat1).sin(lat2)-sin(lat1).cos(lat2).cos(dlong) )
   tmp1=sin(dlong)*cos(lat2);
   tmp2=cos(lat1)*sin(lat2);
   tmp3=sin(lat1)*cos(lat2);
   tmp4=cos(dlong);
   d=atan2(tmp1,tmp2-(tmp3*tmp4));
   tmp1=sin(lat2)-(sin(lat1)*cos(d));
   tmp2=cos(lat1)*sin(d);
   bearing=tmp1/tmp2;
      printf(lcd_putc,"\%4.4f",d);
            printf(lcd_putc,"\n\%4.4f",bearing);
}