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/* cpow.c */
/*
Contributed by Danny Smith
2003-10-20
*/
/* cpow(X, Y) = cexp(X * clog(Y)) */
#include <math.h>
#include <complex.h>
/* Use dll version of pow */
extern double (*_imp__pow) (double, double);
#define pow (*_imp__pow)
double complex cpow (double complex X, double complex Y)
{
double complex Res;
double i;
double r = hypot (__real__ X, __imag__ X);
if (r == 0.0)
{
__real__ Res = __imag__ Res = 0.0;
}
else
{
double rho;
double theta;
i = carg (X);
theta = i * __real__ Y;
if (__imag__ Y == 0.0)
/* This gives slightly more accurate results in these cases. */
rho = pow (r, __real__ Y);
else
{
r = log (r);
/* rearrangement of cexp(X * clog(Y)) */
theta += r * __imag__ Y;
rho = exp (r * __real__ Y - i * __imag__ Y);
}
__real__ Res = rho * cos (theta);
__imag__ Res = rho * sin (theta);
}
return Res;
}
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