/*  scfccosh.cpp  by K.Tsuru  */
// function ID = 9109
/*****************************************
SComplex class
It returns cosh(z).
Let z = x+iy,
cosh(z) = cosh(x)*cos(y)+i*sinh(x)sin(y).
*****************************************/
#ifndef SN_H
#include "sn.h"
#endif

#define UseCSBSccosh 1

SComplex Ccosh(const SComplex& z)
{
 #if UseCSBSccosh //  16.06 sec
    SDouble chx, shx, cy, sy, x(Re(z)), y(Im(z));

    Hyperbolic(x, chx, shx); // chx = cosh(x) shx = sinh(x)
    CosSinBS(y, cy, sy);     // cy = cos(y), sy = sin(y);

    return SComplex(chx*cy, shx*sy);
 #else  // 16.16 sec
    SDouble rr, ri, sh, s, c;
    sh = Sinh(z.Real());
    s = Sin(z.Imag());

    if( (s.PreferSpeed() == ON) && (s.NetRdxExp() > -2) ){
        c = Sqrt(1.0-s*s);      // |s| is O(1.0).
    }else c = Cos(z.Imag());    // |s| is very small.

    rr = Sqrt(1.0+sh*sh)*c; // cosh(x)*cos(y)
    ri = sh*s;              // sinh(x)*sin(y)

    return SComplex(rr, ri);
 #endif
}