#include "TrueBASIC.h"
void acceleration(double position[], double accel[], double *GM);

void acceleration(double position[], double accel[], double *GM)
{
	int i;
	double r2, r3;
	
	r2 = position[1]*position[1] + position[2]*position[2];
	r3 = r2*sqrt(r2);
	for(i = 1; i <= 2; ++i)
	{
		accel[i] = -(*GM)*position[i]/r3;
	}
}