--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/timeToCollision.py	Mon Feb 03 15:39:12 2014 -0500
@@ -0,0 +1,34 @@
+def timeToCollision(obj1,obj2,collisionDistanceThreshold,frameNum,framePerSecond):
+
+    import numpy as np
+
+    x1 = obj1.getPositionAtInstant(frameNum).x
+    y1 = obj1.getPositionAtInstant(frameNum).y
+    x2 = obj2.getPositionAtInstant(frameNum).x
+    y2 = obj2.getPositionAtInstant(frameNum).y
+    v1x = obj1.getVelocityAtInstant(frameNum).x * framePerSecond
+    v1y = obj1.getVelocityAtInstant(frameNum).y * framePerSecond
+    v2x = obj2.getVelocityAtInstant(frameNum).x * framePerSecond
+    v2y = obj2.getVelocityAtInstant(frameNum).y * framePerSecond
+    l = collisionDistanceThreshold
+
+    a = pow(v1x-v2x,2) + pow(v1y-v2y,2)
+    b = 2 * ((x1-x2) * (v1x-v2x) + (y1-y2) * (v1y-v2y))
+    c = pow(x1-x2,2) + pow(y1-y2,2) - pow(l,2)
+    
+    if pow(b,2) >= 4*a*c:
+        ttc1 = (-b + np.sqrt(pow(b,2) - 4*a*c)) / (2*a)
+        ttc2 = (-b - np.sqrt(pow(b,2) - 4*a*c)) / (2*a)
+        if ttc1 >= 0 and ttc2 >= 0:
+            ttc = min(ttc1,ttc2)
+        else:
+            if ttc1 < 0:
+                ttc = ttc2
+            if ttc2 < 0:
+                ttc = ttc1
+            if ttc1 < 0 and ttc2 < 0:
+                ttc = []
+    else:
+        ttc = []
+
+    return ttc