libf2c/libF77/pow_zz.c

   1 #include "f2c.h"
   2
   3 #ifdef KR_headers
   4 double log(), exp(), cos(), sin(), atan2(), f__cabs();
   5 VOID pow_zz(r,a,b) doublecomplex *r, *a, *b;
   6 #else
   7 #undef abs
   8 #include <math.h>
   9 extern double f__cabs(double,double);
  10 void pow_zz(doublecomplex *r, doublecomplex *a, doublecomplex *b)
  11 #endif
  12 {
  13 double logr, logi, x, y;
  14
  15 logr = log( f__cabs(a->r, a->i) );
  16 logi = atan2(a->i, a->r);
  17
  18 x = exp( logr * b->r - logi * b->i );
  19 y = logr * b->i + logi * b->r;
  20
  21 r->r = x * cos(y);
  22 r->i = x * sin(y);
  23 }