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authorTavian Barnes <tavianator@gmail.com>2011-05-15 15:54:56 -0600
committerTavian Barnes <tavianator@gmail.com>2011-05-15 15:58:05 -0600
commita5a6b94c038e01ebf1e2de0a0774a69b02fb8e1e (patch)
tree66a4b977fff9f0119456b6c5a3398d25976f6c53 /libdimension/tests/polynomial.c
parent130cbc32499ade9235873bc5d575816f80636916 (diff)
downloaddimension-a5a6b94c038e01ebf1e2de0a0774a69b02fb8e1e.tar.xz
Group tests and benchmarks with the corresponding source code.
Diffstat (limited to 'libdimension/tests/polynomial.c')
-rw-r--r--libdimension/tests/polynomial.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/libdimension/tests/polynomial.c b/libdimension/tests/polynomial.c
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+++ b/libdimension/tests/polynomial.c
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+/*************************************************************************
+ * Copyright (C) 2010-2011 Tavian Barnes <tavianator@tavianator.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)
+{
+ /* Treat warnings as errors for tests */
+ dmnsn_die_on_warnings(true);
+
+ 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;
+}