Add Distance.raw_distance, to compliment max_distance.

beets/autotag/match.py

@@ -308,14 +308,11 @@ class Distance(object):
 
     @property
     def distance(self):
-        """Returns an overall weighted distance across all penalties.
+        """Returns a weighted and normalised distance across all penalties.
         """
-        dist = 0.0
-        for key, penalty in self._penalties.iteritems():
-            dist += sum(penalty) * weights[key].as_number()
         dist_max = self.max_distance
         if dist_max:
-            return dist / dist_max
+            return self.raw_distance / self.max_distance
         return 0.0
 
     @property
@@ -327,6 +324,15 @@ class Distance(object):
             dist_max += len(penalty) * weights[key].as_number()
         return dist_max
 
+    @property
+    def raw_distance(self):
+        """Returns the raw (denormalised) distance.
+        """
+        dist_raw = 0.0
+        for key, penalty in self._penalties.iteritems():
+            dist_raw += sum(penalty) * weights[key].as_number()
+        return dist_raw
+
     @property
     def sorted(self):
         """Returns a list of (dist, key) pairs, with `dist` being the weighted

test/test_autotag.py

@@ -200,6 +200,14 @@ class DistanceTest(unittest.TestCase):
         self.dist.add('medium', 0.0)
         self.assertEqual(self.dist.max_distance, 5.0)
 
+    def test_raw_distance(self):
+        config['match']['distance_weights']['album'] = 3.0
+        config['match']['distance_weights']['medium'] = 1.0
+        self.dist.add('album', 0.5)
+        self.dist.add('medium', 0.25)
+        self.dist.add('medium', 0.5)
+        self.assertEqual(self.dist.raw_distance, 2.25)
+
     def test_sorted(self):
         config['match']['distance_weights']['album'] = 4.0
         config['match']['distance_weights']['medium'] = 2.0