work in progress

nilmtools/decimate.py

@@ -53,7 +53,10 @@ def main():
                                       "decimate_factor": args.factor })
 
     # Process it
-    
+    f.process(maxlen = 600, function = decimate, args = (factor,))
+
+def decimate(data, start, end, factor):
+    pass
 
 if __name__ == "__main__":
     main()

nilmtools/filter.py

@@ -95,13 +95,36 @@ class Filter(object):
 
     # Misc helpers
     def stream_info_string(self, info):
+        """Print stream info as a string"""
         return sprintf("%s (%s), %.2fM rows, %.2f hours",
                        info[0], info[1], info[4] / 1e6, info[5] / 3600)
 
     def interval_string(self, interval):
+        """Print interval as a string"""
         return sprintf("[ %s -> %s ]", format_time(interval[0]),
                        format_time(interval[1]))
 
+    # Main processing helper
+    def process(self, function, maxlen, args):
+        """Process data in chunks.
+
+        function: function to process the data
+        maxlen: maximum length of data to pass to function, in seconds
+        args: tuple containing extra arguments to pass to function
+
+        'function' should be defined like:
+            function(data, start, end, *args)
+        It will be passed a block of data from the source stream,
+        the start and end times of that block, and any arguments
+        that were passed to process in 'args'.  The total
+        length of the interval will be at most 'maxlen' seconds.
+
+        'function' should transform the data as desired, and return
+        a new list of data, which will be inserted into the
+        destination stream."""
+        for (start, end) in self.intervals():
+            if (end - start) 
+            return
 
 def main():
     # This is just a dummy function; actual filters can use the other