--- a/python/events.py	Sun Jun 16 23:44:36 2013 -0400
+++ b/python/events.py	Mon Jun 17 16:26:11 2013 -0400
@@ -87,12 +87,27 @@
                 minDistance[instant] = distance.min()
             self.addIndicator(indicators.SeverityIndicator('Minimum Distance', minDistance))
 
-    def computeCollisionPoints(self, predictionParameters, collisionDistanceThreshold, timeHorizon):
-        if self.roadUser1.features and self.roadUser2.features:
-            collisionPoints = prediction.computeCollisions(self.roadUser1, self.roadUser2, predictionParameters, collisionDistanceThreshold, timeHorizon)
-            self.addIndicator(indicators.SeverityIndicator('Collision Points', collisionPoints))	
+    def computeCrossingsCollisions(self, predictionParameters, collisionDistanceThreshold, timeHorizon, computeCZ = False, debug = False, timeInterval = None):
+        '''Computes all crossing and collision points at each common instant for two road users. '''
+        self.collisionPoints={}
+        TTCs = {}
+        if computeCZ:
+            self.crossingZones={}
+
+        if timeInterval:
+            commonTimeInterval = timeInterval
         else:
-            print('Features not associated with objects')
+            commonTimeInterval = self.timeInterval
+        for i in list(commonTimeInterval)[:-1]: # do not look at the 1 last position/velocities, often with errors
+            self.collisionPoints[i], self.crossingZones[i] = prediction.computeCrossingsCollisionsAtInstant(i, self.roadUser1, self.roadUser2, predictionParameters, collisionDistanceThreshold, timeHorizon, computeCZ, debug)
+            TTCs[i] = prediction.computeExpectedIndicator(self.collisionPoints[i])
+        self.addIndicator(indicators.SeverityIndicator('TTC', TTCs))
+        
+        if computeCZ:
+            pPETs = {}
+            for i in list(commonTimeInterval)[:-1]:
+                pPETs[i] = prediction.computeExpectedIndicator(self.crossingZones[i])
+                self.addIndicator(indicators.SeverityIndicator('pPET', pPETs))
 
     def addVideoFilename(self,videoFilename):
         self.videoFilename= videoFilename