Initial import

git-svn-id: svn://cook.msm.cam.ac.uk:745/diff-tomo/dtr@1 bf6ca9ba-c028-0410-8290-897cf20841d1

1 files changed, 44 insertions, 0 deletions

diff --git a/src/utils.c b/src/utils.c
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+/*
+ * utils.c
+ *
+ * Utility stuff
+ *
+ * (c) 2007 Thomas White <taw27@cam.ac.uk>
+ *  dtr - Diffraction Tomography Reconstruction
+ *
+ */
+
+#include <math.h>
+
+/* Return the MOST POSITIVE of two numbers */
+unsigned int biggest(signed int a, signed int b) {
+	if ( a>b ) {
+		return a;
+	}
+	return b;
+}
+
+/* Return the LEAST POSITIVE of two numbers */
+unsigned int smallest(signed int a, signed int b) {
+	if ( a<b ) {
+		return a;
+	}
+	return b;
+}
+
+double distance(double x1, double y1, double x2, double y2) {
+	return sqrt((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1));
+}
+
+double modulus(double x, double y, double z) {
+	return sqrt(x*x + y*y + z*z);
+}
+
+/* Angle between two vectors.  Answer in degrees */
+double angle_between(double x1, double y1, double z1, double x2, double y2, double z2) {
+
+	double mod1 = modulus(x1, y1, z1);
+	double mod2 = modulus(x2, y2, z2);
+	return ((acos((x1*x2 + y1*y2 + z1*z2) / (mod1*mod2)))/M_PI) * 180;
+
+}