56 lines
959 B
C
56 lines
959 B
C
|
/* csqrtl.c */
|
||
|
|
/*
|
||
|
|
Contributed by Danny Smith
|
||
|
|
2005-01-04
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <math.h>
|
||
|
|
#include <complex.h>
|
||
|
|
|
||
|
|
long double complex csqrtl (long double complex Z)
|
||
|
|
{
|
||
|
|
long double complex Res;
|
||
|
|
long double r;
|
||
|
|
long double x = __real__ Z;
|
||
|
|
long double y = __imag__ Z;
|
||
|
|
|
||
|
|
if (y == 0.0L)
|
||
|
|
{
|
||
|
|
if (x < 0.0L)
|
||
|
|
{
|
||
|
|
__real__ Res = 0.0L;
|
||
|
|
__imag__ Res = sqrtl (-x);
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
__real__ Res = sqrtl (x);
|
||
|
|
__imag__ Res = 0.0L;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
else if (x == 0.0L)
|
||
|
|
{
|
||
|
|
r = sqrtl(0.5L * fabsl (y));
|
||
|
|
__real__ Res = y > 0 ? r : -r;
|
||
|
|
__imag__ Res = r;
|
||
|
|
}
|
||
|
|
|
||
|
|
else
|
||
|
|
{
|
||
|
|
long double t = sqrtl (2.0L * (hypotl (__real__ Z, __imag__ Z) + fabsl (x)));
|
||
|
|
long double u = t / 2.0L;
|
||
|
|
if ( x > 0.0L)
|
||
|
|
{
|
||
|
|
__real__ Res = u;
|
||
|
|
__imag__ Res = y / t;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
__real__ Res = fabsl (y / t);
|
||
|
|
__imag__ Res = y < 0 ? -u : u;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return Res;
|
||
|
|
}
|