Thread: Use some quick help

Hello again. I don't know what is wrong with the following equation, but I keep getting this error message.

Error 4 error C2676: binary '-' : 'Vector' does not define this operator or a conversion to a type acceptable to the predefined operator

Code:

F*=G*((bodies[i].m*bodies[i++].m)/(sqrt((bodies[i].r.x-bodies[i++].r.x)*(bodies[i++].r.x-bodies[i].r.x)+(bodies[i++].r.y-bodies[i].r.y)*(bodies[i++].r.y-bodies[i].r.y))*sqrt((bodies[i++].r.x-bodies[i].r.x)*(bodies[i++].r.x-bodies[i].r.x)+(bodies[i++].r.y-bodies[i].r.y)*(bodies[i++].r.y-bodies[i].r.y))*sqrt((bodies[i++].r.x-bodies[i].r.x)*(bodies[i++].r.x-bodies[i].r.x)+(bodies[i++].r.y-bodies[i].r.y)*(bodies[i++].r.y-bodies[i].r.y))))*(bodies[i++].r-bodies[i].r);

These are where the types come from

Code:

typedef struct {
	double x;	
	double y;	
} Vector;

typedef struct {
	Vector r;			
	Vector v;	
	double m;	
	char name[MAX_NAME];
} Body;

I'm lost as to what that error is from. Thanks.

At the end of your statement:

Code:

bodies[i++].r-bodies[i].r);

That needs to be an r.x-bodies or an r.y-bodies (I have no idea which).

Thanks! I got it working!