#include "f2c.h" #undef abs #include extern double f__cabs (double, double); void pow_zz (doublecomplex * r, doublecomplex * a, doublecomplex * b) { double logr, logi, x, y; if (a->r == 0.0 && a->i == 0.0) { /* Algorithm below doesn't cope. */ r->r = r->i = 0.0; return; } logr = log (f__cabs (a->r, a->i)); logi = atan2 (a->i, a->r); x = exp (logr * b->r - logi * b->i); y = logr * b->i + logi * b->r; r->r = x * cos (y); r->i = x * sin (y); }