src/complex/transcendental/cl_C_tanh.cc

   1 // tanh().
   2
   3 // General includes.
   4 #include "cl_sysdep.h"
   5
   6 // Specification.
   7 #include "cl_complex.h"
   8
   9
  10 // Implementation.
  11
  12 #include "cl_C.h"
  13 #include "cl_real.h"
  14
  15 const cl_N tanh (const cl_N& x)
  16 {
  17 // Methode:
  18 // x reell -> (/ (sinh x) (cosh x))
  19 // x = a+bi -> (/ (complex (* (sinh a) (cos b)) (* (cosh a) (sin b)))
  20 //                (complex (* (cosh a) (cos b)) (* (sinh a) (sin b))) )
  21         if (realp(x)) {
  22                 DeclareType(cl_R,x);
  23                 var cl_cosh_sinh_t hyp = cl_cosh_sinh(x);
  24                 return hyp.sinh / hyp.cosh;
  25         } else {
  26                 DeclareType(cl_C,x);
  27                 // x=a+bi
  28                 var const cl_R& a = realpart(x);
  29                 var const cl_R& b = imagpart(x);
  30                 var cl_cos_sin_t trig_b = cl_cos_sin(b); // cos(b), sin(b) errechnen
  31                 var cl_cosh_sinh_t hyp_a = cl_cosh_sinh(a); // cosh(a), sinh(a) errechnen
  32                 return
  33                         complex_C(hyp_a.sinh * trig_b.cos, // sinh(a)*cos(b)
  34                                   hyp_a.cosh * trig_b.sin // cosh(a)*sin(b), nicht Fixnum 0
  35                                  )
  36                       / complex(hyp_a.cosh * trig_b.cos, // cosh(a)*cos(b)
  37                                 hyp_a.sinh * trig_b.sin // sinh(a)*sin(b)
  38                                );
  39         }
  40 }