chords!

pytheory/charts.py

@@ -3,7 +3,7 @@ import itertools
 from .systems import SYSTEMS
 from .tones import Tone
 
-MODS = ('', 'm', '5', '7', '9', 'dim', 'm6', 'm7', 'maj7', 'sus')
+MODS = ('', 'maj', 'm', '5', '7', '9', 'dim', 'm6', 'm7', 'maj7')
 
 CHARTS = {}
 CHARTS['western'] = []
@@ -28,10 +28,40 @@ class NamedChord:
     def acceptable_tones(self):
         acceptable = [self.tone]
 
-        acceptable += [self.tone.add(5)]
-        # acceptable += [self.tone.add(3)]
-        acceptable += [self.tone.subtract(5)]
-        # acceptable += [self.tone.subtract(3)]
+
+        # Major third.
+        if self.mod == 'maj':
+            acceptable += [self.tone.add(3)]
+
+        # Minor third.
+        elif self.mod == 'm':
+            acceptable += [self.tone.add(4)]
+
+        # Perfect fifth.
+        elif self.mod == '5':
+            acceptable += [self.tone.add(5)]
+
+        elif self.mod == '7':
+            acceptable += [self.tone.add(7)]
+
+        elif self.mod == '9':
+            acceptable += [self.tone.add(9)]
+
+        elif self.mod == 'dim':
+            acceptable += [self.tone.add(4), self.tone.add(8)]
+
+        elif self.mod == 'm6':
+            acceptable += [self.tone.add(4), self.tone.add(6)]
+
+        elif self.mod == 'm7':
+            acceptable += [self.tone.add(4), self.tone.add(7)]
+
+        elif self.mod == 'maj7':
+            acceptable += [self.tone.add(3), self.tone.add(7)]
+
+        else:
+            acceptable += [self.tone.add(5)]
+            acceptable += [self.tone.subtract(5)]
 
         return tuple(acceptable)
 
@@ -39,7 +69,7 @@ class NamedChord:
     def acceptable_tone_names(self):
         return tuple([tone.name for tone in self.acceptable_tones])
 
-    def possible_fingerings(self, *, fretboard):
+    def _possible_fingerings(self, *, fretboard):
         def find_fingerings(tone):
             fingerings = []
             for j in range(7):
@@ -56,11 +86,40 @@ class NamedChord:
         return tuple(fingering)
 
     def fingerings(self, *, fretboard):
-        return tuple(itertools.product(*self.possible_fingerings(fretboard=fretboard)))
+        return tuple(itertools.product(*self._possible_fingerings(fretboard=fretboard)))
 
-    def fingering(self, *, freboard):
-        possible_fingerings = self.possible_fingerings(freboard=fretboard)
-        return posible_fingerings
+    def fingering(self, *, fretboard, multiple=False):
+        def fingering_score(fingering):
+            def number_of_fingers(fingering):
+                zeros = 0
+                for finger in fingering:
+                    if finger == 0:
+                        zeros += 1
+                return len(fingering) - zeros
+
+            def ascending(fingering):
+                fingering = [f for f in fingering if f != 0]
+
+                return sorted(fingering) == fingering
+
+            ascending = int(ascending(fingering))
+            finger_count = number_of_fingers(fingering)
+            return ascending + (1 / finger_count)
+
+        def gen():
+            fingerings = self.fingerings(fretboard=fretboard)
+            score_map = tuple(map(fingering_score, fingerings))
+            max_score = max(score_map)
+
+            for possible_fingering in fingerings:
+                if fingering_score(possible_fingering) == max_score:
+                    yield possible_fingering
+
+        best_fingerings = tuple([g for g in gen()])
+        if not multiple:
+            return best_fingerings[0]
+        else:
+            return best_fingerings