[unix-history] / usr / src / usr.bin / f77 / libF77 / c_sqrt.c

/*
 *	"@(#)c_sqrt.c	1.1"
 */

#include "complex"

c_sqrt(r, z)
complex *r, *z;
{
double mag, sqrt(), cabs();

if( (mag = cabs(z->real, z->imag)) == 0.)
	r->real = r->imag = 0.;
else if(z->real > 0)
	{
	r->real = sqrt(0.5 * (mag + z->real) );
	r->imag = z->imag / r->real / 2;
	}
else
	{
	r->imag = sqrt(0.5 * (mag - z->real) );
	if(z->imag < 0)
		r->imag = - r->imag;
	r->real = z->imag / r->imag /2;
	}
}
Commit	Line	Data
c788ff04 DW	1	/*
	2	* "@(#)c_sqrt.c 1.1"
	3	*/
	4
	5	#include "complex"
	6
	7	c_sqrt(r, z)
	8	complex r, z;
	9	{
	10	double mag, sqrt(), cabs();
	11
	12	if( (mag = cabs(z->real, z->imag)) == 0.)
	13	r->real = r->imag = 0.;
	14	else if(z->real > 0)
	15	{
	16	r->real = sqrt(0.5 * (mag + z->real) );
	17	r->imag = z->imag / r->real / 2;
	18	}
	19	else
	20	{
	21	r->imag = sqrt(0.5 * (mag - z->real) );
	22	if(z->imag < 0)
	23	r->imag = - r->imag;
	24	r->real = z->imag / r->imag /2;
	25	}
	26	}