diff -r 4fedf7290929 -r 7c3f38dff082 demos/vector.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/demos/vector.py	Sun Apr 20 16:48:24 2008 +0200
@@ -0,0 +1,24 @@
+from math import *
+
+def dot(a,b):
+	sum = 0
+	for i in range(min(len(a),len(b))):
+		sum += a[i]*b[i]
+	return sum
+
+def cross(a,b):
+	return (
+		a[1]*b[2] - a[2]*b[1],
+		a[2]*b[0] - a[0]*b[2],
+		a[0]*b[1] - a[1]*b[0]
+	)
+
+def unit(a):
+	m = mag(a)
+	return (a[0]/m, a[1]/m, a[2]/m)
+
+def mag(a):
+	return sqrt(mag2(a))
+
+def mag2(a):
+	return a[0]*a[0] + a[1]*a[1] + a[2]*a[2]