--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/python/offset-trajectories.py	Tue Sep 20 13:49:01 2011 -0400
@@ -0,0 +1,23 @@
+#! /usr/bin/env python
+import sys
+
+import ubc_utils
+import utils
+
+if len(sys.argv) < 3:
+    print("Usage: %s filename offsetframes")
+    sys.exit()
+
+nFrames = int(sys.argv[2])
+
+def modifyLines(objectNum, lines):
+    result = lines
+    tmp = lines[0].split(" ")
+    firstInstant = int(tmp[1])+nFrames
+    lastInstant = int(tmp[2])+nFrames
+    tmp[1] = str(firstInstant)
+    tmp[2] = str(lastInstant)
+    result[0] = " ".join(tmp)
+    return result
+
+ubc_utils.modifyTrajectoryFile(modifyLines, sys.argv[1], sys.argv[1]+".new")

--- a/python/ubc_utils.py	Mon Sep 19 16:43:28 2011 -0400
+++ b/python/ubc_utils.py	Tue Sep 20 13:49:01 2011 -0400
@@ -80,8 +80,7 @@
     print('read {0} objects'.format(objNum))
 
 def modifyTrajectoryFile(modifyLines, filenameIn, filenameOut):
-    '''Reads filenameIn, replaces the first line with the result of modifyLines and writes the result in filenameOut'''
-    #sortByNum(objects)
+    '''Reads filenameIn, replaces the lines with the result of modifyLines and writes the result in filenameOut'''
     fileIn = utils.openCheck(filenameIn, 'r', True)
     fileOut = utils.openCheck(filenameOut, "w", True)