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[unix-history] / usr / src / usr.bin / f77 / libF77 / pow_zz.c

/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved.  The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
*      @(#)pow_zz.c    5.1     %G%
*/

#include "complex"

pow_zz(r,a,b)
dcomplex *r, *a, *b;
{
double logr, logi, x, y;
double log(), exp(), cos(), sin(), atan2(), cabs();

logr = log( cabs(a->dreal, a->dimag) );
logi = atan2(a->dimag, a->dreal);

x = exp( logr * b->dreal - logi * b->dimag );
y = logr * b->dimag + logi * b->dreal;

r->dreal = x * cos(y);
r->dimag = x * sin(y);
}