/*  scfctan.cpp  by K.Tsuru  */
// function ID = 9114
/*****************************************
SComplex class
It returns tan(z).
Let z = x+iy,
tan(z) = {sin(2*x)+i*sinh(2*y)}/{cos(2*x)+cosh(2*y)}
    1 - exp(2*i*z)
=i*-----------------
    1 + exp(2*i*z)
  
remake on Aug 14, 1995 (since version 2.30)
*****************************************/
#ifndef SN_H
#include "sn.h"
#endif

SComplex Ctan(const SComplex& z)
{
    if(z.IsZero()) return SComplex(0.0);

#if 0  // 31.3 sec
    SDouble den, rr, ri;
    den = Cos(2*z.Real())+Cosh(2*z.Imag());
    den = 1/den;
    rr = Sin(2*z.Real()) * den;
    ri = Sinh(2*z.Imag()) * den;

    return SComplex(rr, ri);
#else // 15.9 sec
    SComplex z2 = 2*MultI(z), ez2 = Cexp(z2), r;

    r = (1.0 - ez2)/(1.0 + ez2);

    return MultI(r);
#endif
}