Honour voltage from MRC header if present

git-svn-id: svn://cook.msm.cam.ac.uk:745/diff-tomo/dtr@11 bf6ca9ba-c028-0410-8290-897cf20841d1

1 files changed, 12 insertions, 0 deletions

diff --git a/src/utils.c b/src/utils.c
index ce7c7f3..4055676 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -42,3 +42,15 @@ double angle_between(double x1, double y1, double z1, double x2, double y2, doub
 	return ((acos((x1*x2 + y1*y2 + z1*z2) / (mod1*mod2)))/M_PI) * 180;
 
 }
+
+/* Wavelength of an electron (in m) given accelerating potential (in V) */
+double lambda(double V) {
+
+	double m = 9.110E-31;
+	double h = 6.625E-34;
+	double e = 1.60E-19;
+	double c = 2.998E8;
+	
+	return h / sqrt(2*m*e*V*(1+(e*V / 2*m*c*c)));
+
+}