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47 lines
938 B
C
47 lines
938 B
C
/*
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FUNCTION
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<<clog10>>, <<clog10f>>---complex base-10 logarithm
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INDEX
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clog10
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INDEX
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clog10f
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ANSI_SYNOPSIS
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#define _GNU_SOURCE
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#include <complex.h>
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double complex clog10(double complex <[z]>);
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float complex clog10f(float complex <[z]>);
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DESCRIPTION
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These functions compute the complex base-10 logarithm of <[z]>.
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<<clog10>> is equivalent to <<clog>>(<[z]>)/<<log>>(10).
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<<clog10f>> is identical to <<clog10>>, except that it performs
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its calculations on <<floats complex>>.
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RETURNS
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The clog10 functions return the complex base-10 logarithm value.
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PORTABILITY
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<<clog10>> and <<clog10f>> are GNU extensions.
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*/
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#include <complex.h>
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#include <math.h>
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double complex
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clog10(double complex z)
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{
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double complex w;
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double p, rr;
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rr = cabs(z);
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p = log10(rr);
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rr = atan2(cimag(z), creal(z)) * M_IVLN10;
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w = p + rr * I;
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return w;
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}
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