SCRIPTS: Added a preprocess python script

Added a script to help preprocessing the raw data. In particular this
script removes duplicates of power measurements that erroneously occur
when the measurement utility hangs and don't save on disk the current
result in time. In this case we read the previous result.

To avoid this we read all the results, and if there are two lines with
the same power measurement values which execution times are really
different we discard the unwanted measure.

utils/preprocess.py

@@ -0,0 +1,42 @@
+#!/usr/bin/env python
+from tempfile import NamedTemporaryFile
+import shutil
+import csv
+
+# Helper function that processes one platform at a time
+def purgeDouble(platform):
+
+    # File containing the unprocessed raw data
+    filename = 'results/' + platform + '/total.dat'
+
+    #Temporary file for storing the changes
+    tempfile = NamedTemporaryFile(delete=False)
+
+    with open(filename, 'rb') as csvFile, tempfile:
+        reader = csv.reader(csvFile, delimiter=',', quotechar='"')
+        writer = csv.writer(tempfile, delimiter=',', quotechar='"')
+
+        # At the first iteration we manually initialize the previousRow value
+        previousRow = []
+        for row in reader:
+
+            # If we are not at the first iteration, the values of two power measurement are equal but the times are really different, it means that the data collection duplicated erroneously a value, so we set to null that field
+            if previousRow != [] and previousRow[2] == row[2] and (float(previousRow[1]) - float(row[1])) > 2.5:
+                print("duplicate found and removed in:")
+                print(previousRow)
+                print(row)
+                row[2] = ''
+            else:
+                row = row
+            writer.writerow(row)
+            previousRow = row
+
+    # Move the temporary file to overwrite the original file
+    shutil.move(tempfile.name, filename)
+
+# List of all the platforms
+platforms = ['cpu', 'gpu-primary', 'gpu-secondary']
+
+# Invoke the purgeDouble function for each platform
+for platform in platforms:
+    purgeDouble(platform)