--- a/numerics/reduce.py	Mon Mar 16 19:31:49 2015 -0700
+++ b/numerics/reduce.py	Mon Mar 16 19:55:41 2015 -0700
@@ -15,13 +15,30 @@
 __all__ = ['ReduceParser']
 
 
-class ReduceParser(argparse.ArgumentParser):
+class ReduceParser(FloatParser):
     """CLI option parser"""
+
+    # reducing function
+    function = lambda x: raise NotImplemented("Abstract base class")
+
     def __init__(self, **kwargs):
-        kwargs.setdefault('formatter_class', argparse.RawTextHelpFormatter)
         kwargs.setdefault('description', __doc__)
         argparse.ArgumentParser.__init__(self, **kwargs)
         self.options = None
 
+    def __call__(self, *args):
 
+        # parse command line options
+        self.parse_args(args or sys.argv[1:])
 
+        # read data
+        columns = self.typed_data()
+        if not columns:
+            self.error("No data given")
+
+        # calculate scalars
+        data = [self.function(column) for column in column]
+
+        # write CSV
+        writer = CSVWriter(options.output)
+        writer.write([data])