newlib/winsup/mingw/mingwex/complex/catanf.c
Danny Smith 9a3412eea8 * mingwex/complex/(cabsf.c cacosf.c cacoshf.c cargf.c casinf.c
casinhf.c catanf.c catanhf.c ccosf.c ccoshf.c cexpf.c cimagf.c
	clogf.c cpowf.c cprojf.c crealf.c csinf.c csinhf.c csqrtf.c
	ctanf.c ctanhf.c): New files.
	* mingwex/Makefile.in (COMPLEX_DISTFILES): Adjust.
	(COMPLEX_OBJS(: Adjust.
	* include/complex.h (cabsf, cacosf, cacoshf, cargf, casinf.
	casinhf, catanf, catanhf, ccosf, ccoshf, cexpf, cimagf, clogf,
	cpowf, cprojf, crealf, csinf, csinhf, csqrtf, ctanf, ctanhf):
	Declare.
2004-12-25 23:56:19 +00:00

50 lines
903 B
C
Executable File

/* catanf.c */
/*
Contributed by Danny Smith
2004-12-24
FIXME: This needs some serious numerical analysis.
*/
#include <math.h>
#include <complex.h>
#include <errno.h>
/* catan (z) = -I/2 * clog ((I + z) / (I - z)) */
float complex
catanf (float complex Z)
{
float complex Res;
float complex Tmp;
float x = __real__ Z;
float y = __imag__ Z;
if ( x == 0.0f && (1.0f - fabsf (y)) == 0.0f)
{
errno = ERANGE;
__real__ Res = HUGE_VALF;
__imag__ Res = HUGE_VALF;
}
else if (isinf (hypotf (x, y)))
{
__real__ Res = (x > 0 ? M_PI_2 : -M_PI_2);
__imag__ Res = 0.0f;
}
else
{
__real__ Tmp = - x;
__imag__ Tmp = 1.0f - y;
__real__ Res = x;
__imag__ Res = y + 1.0f;
Tmp = clogf (Res/Tmp);
__real__ Res = - 0.5f * __imag__ Tmp;
__imag__ Res = 0.5f * __real__ Tmp;
}
return Res;
}