--- a/python/moving.py	Wed Jul 17 18:19:08 2013 -0400
+++ b/python/moving.py	Thu Jul 18 02:08:51 2013 -0400
@@ -687,6 +687,18 @@
     def play(self, videoFilename, homography = None):
         cvutils.displayTrajectories(videoFilename, [self], homography, self.getFirstInstant(), self.getLastInstant())
 
+    def speedDiagnostics(self, display = False):
+        from numpy import std
+        speeds = self.getSpeeds()
+        coef = utils.linearRegression(range(len(speeds)), speeds)
+        print(speeds[-2]-speeds[1], std(speeds), coef[0])
+        if display:
+            from matplotlib.pyplot import figure, plot
+            figure(1)
+            self.draw()
+            figure(2)
+            plot(list(self.getTimeInterval()), speeds)
+
     def getInstantsCrossingLane(self, p1, p2):
         '''Returns the instant(s)
         at which the object passes from one side of the segment to the other

--- a/python/storage.py	Wed Jul 17 18:19:08 2013 -0400
+++ b/python/storage.py	Thu Jul 18 02:08:51 2013 -0400
@@ -364,9 +364,9 @@
     '''Reads data from the trajectory data provided by NGSIM project
     and converts to our current format.'''
     if append:
-        out = open(outFile,'a')
+        out = utils.openCheck(outFile,'a')
     else:
-        out = open(outFile,'w')
+        out = utils.openCheck(outFile,'w')
     nObjectsPerType = [0,0,0]
 
     features = loadNgsimFile(inFile, sequenceNum)
@@ -391,11 +391,17 @@
         f.write(s+'\n')
 
 def writeTrajectoriesToCsv(filename, objects):
-    f = open(filename, 'w')
+    f = utils.openCheck(filename, 'w')
     for i,obj in enumerate(objects):
         writePositionsToCsv(f, obj)
     f.close()
 
+def writeList(filename, l):
+    f = utils.openCheck(filename, 'w')
+    for x in l:
+        f.write('{}\n'.format(x))
+    f.close()
+
 if __name__ == "__main__":
     import doctest
     import unittest