50 lines
724 B
C
50 lines
724 B
C
/*
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* (c) copyright 1988 by the Vrije Universiteit, Amsterdam, The Netherlands.
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* See the copyright notice in the ACK home directory, in the file "Copyright".
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*
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* Author: Ceriel J.H. Jacobs
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*/
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#include <math.h>
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#include <ack/config.h>
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#if ACKCONF_WANT_FLOAT
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/* $Id$ */
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double
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hypot(double x, double y)
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{
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/* Computes sqrt(x*x+y*y), avoiding overflow */
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if (x < 0)
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x = -x;
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if (y < 0)
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y = -y;
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if (x > y)
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{
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double t = y;
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y = x;
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x = t;
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}
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/* sqrt(x*x+y*y) = sqrt(y*y*(x*x/(y*y)+1.0)) = y*sqrt(x*x/(y*y)+1.0) */
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if (y == 0.0)
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return 0.0;
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x /= y;
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return y * sqrt(x * x + 1.0);
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}
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struct complex
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{
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double r, i;
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};
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double
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cabs(struct complex p_compl)
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{
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return hypot(p_compl.r, p_compl.i);
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}
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#endif
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