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/*************************************************************************
* Copyright (C) 2010-2011 Tavian Barnes <tavianator@gmail.com> *
* *
* This file is part of The Dimension Test Suite. *
* *
* The Dimension Test Suite is free software; you can redistribute it *
* and/or modify it under the terms of the GNU General Public License as *
* published by the Free Software Foundation; either version 3 of the *
* License, or (at your option) any later version. *
* *
* The Dimension Test Suite is distributed in the hope that it will be *
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty *
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/>. *
*************************************************************************/
/*
* Basic test of numerical polynomial root-finder
*/
#include "dimension.h"
#include <stddef.h>
#include <stdio.h>
int
main(void)
{
/* Set the resilience low for tests */
dmnsn_set_resilience(DMNSN_SEVERITY_LOW);
double poly[6], x[5];
/* poly[] = (x + 1)*(x - 1.2345)*(x - 2.3456)*(x - 5)*(x - 100) */
poly[5] = 1.0;
poly[4] = -107.5801;
poly[3] = 770.2260432;
poly[2] = -1215.2863928;
poly[1] = -646.270936;
poly[0] = 1447.8216;
size_t n = dmnsn_solve_polynomial(poly, 5, x);
if (n != 4) {
fprintf(stderr,
"--- Wrong number of roots found (%zu, should be %u) ---\n",
n, 4);
return EXIT_FAILURE;
}
for (size_t i = 0; i < n; ++i) {
double evmin = dmnsn_evaluate_polynomial(poly, 5, x[i] - dmnsn_epsilon);
double ev = dmnsn_evaluate_polynomial(poly, 5, x[i]);
double evmax = dmnsn_evaluate_polynomial(poly, 5, x[i] + dmnsn_epsilon);
if (fabs(evmin) < ev || fabs(evmax) < ev) {
fprintf(stderr, "--- Root %.15g is inaccurate! ---\n", x[i]);
return EXIT_FAILURE;
}
}
return EXIT_SUCCESS;
}
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