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/* ctanf.c */
/*
Contributed by Danny Smith
2004-12-24
*/
#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)) */
float complex ctanf (float complex Z)
{
float complex Res;
float two_I = 2.0f * __imag__ Z;
float two_R = 2.0f * __real__ Z;
float denom = cosf (two_R) + coshf (two_I);
if (denom == 0.0f)
{
errno = ERANGE;
__real__ Res = HUGE_VALF;
__imag__ Res = HUGE_VALF;
}
else if (isinf (denom))
{
errno = ERANGE;
__real__ Res = 0.0;
__imag__ Res = two_I > 0 ? 1.0f : -1.0f;
}
else
{
__real__ Res = sinf (two_R) / denom;
__imag__ Res = sinhf (two_I) / denom;
}
return Res;
}
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