[unix-history] / usr / src / libm / hypot.c

/*
 * sqrt(a^2 + b^2)
 *	(but carefully)
 */

double sqrt();
double
hypot(a,b)
double a,b;
{
	double t;
	if(a<0) a = -a;
	if(b<0) b = -b;
	if(a > b) {
		t = a;
		a = b;
		b = t;
	}
	if(b==0) return(0.);
	a /= b;
	/*
	 * pathological overflow possible
	 * in the next line.
	 */
	return(b*sqrt(1. + a*a));
}

struct	complex
{
	double	r;
	double	i;
};

double
cabs(arg)
struct complex arg;
{
	double hypot();

	return(hypot(arg.r, arg.i));
}
Commit	Line	Data
5d130d40 RM	1	/*
	2	* sqrt(a^2 + b^2)
	3	* (but carefully)
	4	*/
	5
	6	double sqrt();
	7	double
	8	hypot(a,b)
	9	double a,b;
	10	{
	11	double t;
	12	if(a<0) a = -a;
	13	if(b<0) b = -b;
	14	if(a > b) {
	15	t = a;
	16	a = b;
	17	b = t;
	18	}
	19	if(b==0) return(0.);
	20	a /= b;
	21	/*
	22	* pathological overflow possible
	23	* in the next line.
	24	*/
	25	return(bsqrt(1. + aa));
	26	}
	27
	28	struct complex
	29	{
	30	double r;
	31	double i;
	32	};
	33
	34	double
	35	cabs(arg)
	36	struct complex arg;
	37	{
	38	double hypot();
	39
	40	return(hypot(arg.r, arg.i));
	41	}