42 lines
815 B
C
Executable File
42 lines
815 B
C
Executable File
/* ctanl.c */
|
|
|
|
/*
|
|
Contributed by Danny Smith
|
|
2005-01-04
|
|
*/
|
|
|
|
#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)) */
|
|
|
|
long double complex ctanl (long double complex Z)
|
|
{
|
|
long double complex Res;
|
|
long double two_I = 2.0L * __imag__ Z;
|
|
long double two_R = 2.0L * __real__ Z;
|
|
long double denom = cosl (two_R) + coshl (two_I);
|
|
if (denom == 0.0L)
|
|
{
|
|
errno = ERANGE;
|
|
__real__ Res = HUGE_VALL;
|
|
__imag__ Res = HUGE_VALL;
|
|
}
|
|
else if (isinf (denom))
|
|
{
|
|
errno = ERANGE;
|
|
__real__ Res = 0.0;
|
|
__imag__ Res = two_I > 0 ? 1.0L : -1.0L;
|
|
}
|
|
else
|
|
{
|
|
__real__ Res = sinl (two_R) / denom;
|
|
__imag__ Res = sinhl (two_I) / denom;
|
|
}
|
|
return Res;
|
|
}
|
|
|