/* Traverses `tree' in order and generates an array of `ellipse's 
   corresponding to ellipses centred at the points in `tree' with semi-x 
   axis a  and semi-y axis b */
void makeellipseinorder(point *tree,
			ellipse *ellipses,
			int *counter,
			double a,
			double b
			);

/* Traverses `tree' in order and generates an array of `ellipse's 
   corresponding to the ellipses centred at the points in `tree' with 
   semi-x axis a and semi-y axis b */
void makeellipseinorder_min(point *tree,
			    ellipse *ellipses,
			    int *counter,
			    double a,
			    double b
			    );
