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authorTavian Barnes <tavianator@gmail.com>2010-11-01 02:49:52 -0400
committerTavian Barnes <tavianator@gmail.com>2010-11-01 02:49:52 -0400
commit5226e19e3bf2e082b02dec9e856e2613744c8571 (patch)
tree1174814d83ab5ddd1b6fed8f227220693ad4c52e /libdimension
parent80388b952b5844261e711e8da5a59c34b4919da7 (diff)
downloaddimension-5226e19e3bf2e082b02dec9e856e2613744c8571.tar.xz
More numerical tweaks.
Diffstat (limited to 'libdimension')
-rw-r--r--libdimension/dimension/geometry.h2
-rw-r--r--libdimension/polynomial.c11
2 files changed, 12 insertions, 1 deletions
diff --git a/libdimension/dimension/geometry.h b/libdimension/dimension/geometry.h
index 4c4f8b8..6ff9941 100644
--- a/libdimension/dimension/geometry.h
+++ b/libdimension/dimension/geometry.h
@@ -63,7 +63,7 @@ typedef struct dmnsn_bounding_box { dmnsn_vector min, max; } dmnsn_bounding_box;
/* Constants */
-#define dmnsn_epsilon 1.0e-9
+#define dmnsn_epsilon 1.0e-10
static const dmnsn_vector dmnsn_zero = { 0.0, 0.0, 0.0 };
static const dmnsn_vector dmnsn_x = { 1.0, 0.0, 0.0 };
diff --git a/libdimension/polynomial.c b/libdimension/polynomial.c
index 6e2aed2..ab80f69 100644
--- a/libdimension/polynomial.c
+++ b/libdimension/polynomial.c
@@ -57,6 +57,15 @@ dmnsn_real_degree(const double poly[], size_t degree)
return 0;
}
+/* Divide each coefficient by the leading coefficient */
+static inline void
+dmnsn_normalize_polynomial(double poly[], size_t degree)
+{
+ for (size_t i = 0; i <= degree; ++i) {
+ poly[i] /= poly[degree];
+ }
+}
+
/* Eliminate trivial zero roots from poly[] */
static inline void
dmnsn_eliminate_zero_roots(double poly[], size_t *degree)
@@ -285,6 +294,8 @@ dmnsn_solve_polynomial(const double poly[], size_t degree, double x[])
/* Account for leading zero coefficients */
degree = dmnsn_real_degree(p, degree);
+ /* Normalize the leading coefficient to 1.0 */
+ dmnsn_normalize_polynomial(p, degree);
/* Eliminate simple zero roots */
dmnsn_eliminate_zero_roots(p, &degree);