/*
 *			a n g l e . c
 */

/*)LIBRARY
*/

#ifdef DOCUMENTATION

title	angle	
index		

synopsis

	int

description


bugs

author

	Machiavelli Systems

#endif/*
 *	A N G L E (  ) - Given a directional cosine & a sine return an angle (radians)
 *
 *		PLEASE MOVE ME TO A LIBRARY
 *
 *	MOD LOG:
 *			9-FEB-85 TG	Conversion from B4S.
 *
 *	LIBRARIES:	CMATH	(PML or equivalent)
 *
 */

#define	PI	3.1415927		/* PI */
#define PIX2	PI * 2.0

double	angle(cs, sn)
double	cs, sn;
{
	double	angl, datan();

	angl = datan(sn/cs);

	if (angl < 0.0)
		angl = angl + PIX2;
	
	if ((angl > PI) && (sn > 0.0))
		angl = angl - PI;

	if ((angl < PI) && (sn < 0.0))
		angl = angl + PI;

	if ((angl == 0.0) && (cs < 0.0))
		angl = PI;

	return(angl);
}