File: z_sqrt.c

package info (click to toggle)
scilab 2.4-1
  • links: PTS
  • area: non-free
  • in suites: potato, slink
  • size: 55,196 kB
  • ctags: 38,019
  • sloc: ansic: 231,970; fortran: 148,976; tcl: 7,099; makefile: 4,585; sh: 2,978; csh: 154; cpp: 101; asm: 39; sed: 5
file content (29 lines) | stat: -rw-r--r-- 492 bytes parent folder | download | duplicates (4) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
 
#include "f2c.h"

#ifdef KR_headers
double sqrt(), f__cabs();
VOID z_sqrt(r, z) doublecomplex *r, *z;
#else
#undef abs
#include "math.h"
extern double f__cabs(double, double);
void z_sqrt(doublecomplex *r, doublecomplex *z)
#endif
{
double mag;

if( (mag = f__cabs(z->r, z->i)) == 0.)
	r->r = r->i = 0.;
else if(z->r > 0)
	{
	r->r = sqrt(0.5 * (mag + z->r) );
	r->i = z->i / r->r / 2;
	}
else
	{
	r->i = sqrt(0.5 * (mag - z->r) );
	if(z->i < 0)
		r->i = - r->i;
	r->r = z->i / r->i / 2;
	}
}