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