[Pybrainsim-activity] SF.net SVN: pybrainsim:[96] trunk/src/Experiment.py

[<rg...@us...>]

Revision: 96
          http://pybrainsim.svn.sourceforge.net/pybrainsim/?rev=96&view=rev
Author:   rgoj
Date:     2009-08-07 10:21:20 +0000 (Fri, 07 Aug 2009)

Log Message:
-----------
* getRecordingSlice now needs only stimulus time as input
* Changed the way start and end indices are calculated in getRecordingSlice
* Added a warning to getERP that prints out a message if epochs are of different length
* Corrected a mistake that caused the average to not be an average, but just a sum

Modified Paths:
--------------
    trunk/src/Experiment.py

Modified: trunk/src/Experiment.py
===================================================================
--- trunk/src/Experiment.py	2009-08-07 10:16:59 UTC (rev 95)
+++ trunk/src/Experiment.py	2009-08-07 10:21:20 UTC (rev 96)
@@ -82,22 +82,31 @@
                     if timePoint > self.timePoints[i-1]:
                         return i
 
-    def getRecordingSlice(self, sliceStart, sliceDuration, sliceChannel=0):
-        startIndex = self.findNearestTimeIndex(sliceStart)
-        endIndex = self.findNearestTimeIndex(sliceStart + sliceDuration)
+    def getRecordingSlice(self, stimulus, sliceChannel=0):
+        stimulusIndex = self.findNearestTimeIndex(stimulus)
+        timeStep = 1.0 / self.samplingFrequency
+        startIndex = int(stimulusIndex - (self.baseline // timeStep))
+        endIndex = int(stimulusIndex + 1 + ((self.epochDuration - self.baseline) // timeStep))
+
         return self.recording[sliceChannel][startIndex:endIndex]
 
     def getERP(self, stimulusNumber=0):
         stimuli = self.stimulusTimes[stimulusNumber]
         epochs = []
         for i in range(len(stimuli)):
-            epochs.append(self.getRecordingSlice(stimuli[i] - self.baseline, self.epochDuration))
+            epochs.append(self.getRecordingSlice(stimuli[i]))
         
+        for i in range(len(epochs)):
+            if i == 0:
+                continue
+            elif (len(epochs[i]) != len(epochs[i-1])):
+                print str(len(epochs[i])) + " " + str(len(epochs[i-1]))
+                print "EPOCHS OF DIFFERENT LENGTHS!!!"
+
         average = list(zeros(len(epochs[0])))
         for i in range(len(epochs)):
             for j in range(len(epochs[i])):
-                average[j] += epochs[i][j]
-
+                average[j] += epochs[i][j] / len(epochs)
         return average        
 
     def plotRecording(self):


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