27dcc451f4
2002-11-19 Toon Moene <toon@moene.indiv.nluug.nl> PR fortran/8587 * libF77/pow_zz.c: Handle (0.0, 0.0) ** power. 2002-11-19 Toon Moene <toon@moene.indiv.nluug.nl> PR fortran/8587 * news.texi: Show PR fortran/8587 fixed. From-SVN: r59280
26 lines
500 B
C
26 lines
500 B
C
#include "f2c.h"
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#undef abs
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#include <math.h>
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extern double f__cabs (double, double);
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void
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pow_zz (doublecomplex * r, doublecomplex * a, doublecomplex * b)
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{
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double logr, logi, x, y;
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if (a->r == 0.0 && a->i == 0.0)
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{
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/* Algorithm below doesn't cope. */
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r->r = r->i = 0.0;
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return;
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}
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logr = log (f__cabs (a->r, a->i));
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logi = atan2 (a->i, a->r);
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x = exp (logr * b->r - logi * b->i);
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y = logr * b->i + logi * b->r;
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r->r = x * cos (y);
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r->i = x * sin (y);
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}
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