src/complex/elem/cl_C_mul.cc

   1 // binary operator *
   2
   3 // General includes.
   4 #include "base/cl_sysdep.h"
   5
   6 // Specification.
   7 #include "cln/complex.h"
   8
   9
  10 // Implementation.
  11
  12 #include "complex/cl_C.h"
  13 #include "cln/real.h"
  14
  15 namespace cln {
  16
  17 const cl_N operator* (const cl_N& x, const cl_N& y)
  18 {
  19 // Methode:
  20 // x,y beide reell -> klar.
  21 // x=a, y=b+ci -> (a*b)+(a*c)i
  22 // x=a+bi, y=c -> (a*c)+(b*c)i
  23 // x=a+bi, y=c+di -> (a*c-b*d)+(a*d+b*c)i
  24         if (realp(x)) {
  25                 DeclareType(cl_R,x);
  26                 if (realp(y)) {
  27                         DeclareType(cl_R,y);
  28                         return x*y;
  29                 } else {
  30                         DeclareType(cl_C,y);
  31                         // x=a, y=b+ci
  32                         var const cl_R& a = x;
  33                         var const cl_R& b = realpart(y);
  34                         var const cl_R& c = imagpart(y);
  35                         return complex(a*b,a*c);
  36                 }
  37         } else {
  38                 DeclareType(cl_C,x);
  39                 if (realp(y)) {
  40                         DeclareType(cl_R,y);
  41                         // x=a+bi, y=c
  42                         var const cl_R& a = realpart(x);
  43                         var const cl_R& b = imagpart(x);
  44                         var const cl_R& c = y;
  45                         return complex(a*c,b*c);
  46                 } else {
  47                         DeclareType(cl_C,y);
  48                         // x=a+bi, y=c+di
  49                         var const cl_R& a = realpart(x);
  50                         var const cl_R& b = imagpart(x);
  51                         var const cl_R& c = realpart(y);
  52                         var const cl_R& d = imagpart(y);
  53                         return complex(a*c-b*d,a*d+b*c);
  54                 }
  55         }
  56 }
  57
  58 }  // namespace cln