newlib-cygwin/winsup/mingw/mingwex/complex/cpowf.c

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/* cpowf.c */
/*
Contributed by Danny Smith
2004-12-24
*/
/* cpow(X, Y) = cexp(X * clog(Y)) */
#include <math.h>
#include <complex.h>
float complex cpowf (float complex X, float complex Y)
{
float complex Res;
float i;
float r = _hypot (__real__ X, __imag__ X);
if (r == 0.0f)
{
__real__ Res = __imag__ Res = 0.0;
}
else
{
float rho;
float theta;
i = cargf (X);
theta = i * __real__ Y;
if (__imag__ Y == 0.0f)
/* This gives slightly more accurate results in these cases. */
rho = powf (r, __real__ Y);
else
{
r = logf (r);
/* rearrangement of cexp(X * clog(Y)) */
theta += r * __imag__ Y;
rho = expf (r * __real__ Y - i * __imag__ Y);
}
__real__ Res = rho * cosf (theta);
__imag__ Res = rho * sinf (theta);
}
return Res;
}