newlib/winsup/mingw/mingwex/complex/ctan.c
Danny Smith 3c7a7a5fca Add ISO C99 complex support for doubles.
* include/complex.h: New file.
	* mingwex/complex: New directory.
	* mingwex/complex/cabs.c: New file.
	* mingwex/complex/cacos.c: New file.
	* mingwex/complex/cacosh.c: New file.
	* mingwex/complex/casin.c: New file.
	* mingwex/complex/casinh.c: New file.
	* mingwex/complex/catan.c: New file.
	* mingwex/complex/catanh.c: New file.
	* mingwex/complex/ccos.c: New file.
	* mingwex/complex/ccosh.c: New file.
	* mingwex/complex/cexp.c: New file.
	* mingwex/complex/cimag.c: New file.
	* mingwex/complex/clog.c: New file.
	* mingwex/complex/cpow.c: New file.
	* mingwex/complex/cproj.c: New file.
	* mingwex/complex/creal.c: New file.
	* mingwex/complex/csin.c: New file.
	* mingwex/complex/csinh.c: New file.
	* mingwex/complex/csqrt.c: New file.
	* mingwex/complex/ctan.c: New file.
	* mingwex/complex/ctanh.c: New file.
	* mingwex/Makefile.in (COMPLEX_DISTFILES): New list of
	files.
	(dist): Use it.
	(COMPLEX_OBJS): New list of objects.
	(LIB_OBJS): Include it in the library.
2003-10-21 09:43:22 +00:00

42 lines
772 B
C

/* ctan.c */
/*
Contributed by Danny Smith
2003-10-20
*/
#include <math.h>
#include <complex.h>
#include <errno.h>
/* ctan (x + I * y) = (sin (2 * x) + I * sinh(2 * y))
/ (cos (2 * x) + cosh (2 * y)) */
double complex ctan (double complex Z)
{
double complex Res;
double two_I = 2.0 * __imag__ Z;
double two_R = 2.0 * __real__ Z;
double denom = cos (two_R) + cosh (two_I);
if (denom == 0.0)
{
errno = ERANGE;
__real__ Res = HUGE_VAL;
__imag__ Res = HUGE_VAL;
}
else if (isinf (denom))
{
errno = ERANGE;
__real__ Res = 0.0;
__imag__ Res = two_I > 0 ? 1.0 : -1.0;
}
else
{
__real__ Res = sin (two_R) / denom;
__imag__ Res = sinh (two_I) / denom;
}
return Res;
}