Add defuzzyfication method 'COG' (centroid/center of gravity). refs #4

arruda · Aug 31, 2017 · 66f91b4 · 66f91b4
1 parent ca1bfa1
commit 66f91b4
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Showing 2 changed files with 46 additions and 7 deletions.
diff --git a/scikit_fuzzy_fcl/fcl_listener.py b/scikit_fuzzy_fcl/fcl_listener.py
@@ -96,21 +96,39 @@ def enterFuzzify_block(self, ctx):
 
     def enterDefuzzify_block(self, ctx):
         label = ctx.ID().getText()
+        override_universe_range = None
+        for item in ctx.defuzzify_item():
+            if item.defuzzify_range():
+                override_universe_range = [float(r.getText()) for r in item.defuzzify_range().REAL()]
+
         # if variable already defined a range then use this to instantiate the consequent
         universe_range = self.vars.get(label, {}).get('range', None)
-
         # but if there's a RANGE defined in the defuzzify block, then it should be used instead
-        for item in ctx.defuzzify_item():
-            defuzzify_range = item.defuzzify_range()
-            if defuzzify_range:
-                universe_range = [float(r.getText()) for r in defuzzify_range.REAL()]
-                break
+        if override_universe_range:
+            universe_range = override_universe_range
+
+        new_consequent = Consequent(universe_range, label=label)
 
         self.consequents[label] = {
-            'value': Consequent(universe_range, label=label),
+            'value': new_consequent,
             'terms': OrderedDict(),
         }
 
+    def map_fcl_defuzz_method_to_skf(self, method):
+        defuzz_map = {
+            'COG': 'centroid'
+        }
+        return defuzz_map[method]
+
+    def enterDefuzzification_method(self, ctx):
+        consequent_label = ctx.parentCtx.parentCtx.ID().getText()
+        consequent = self.consequents[consequent_label].get('value')
+
+        fcl_method = ctx.getChild(2).getText()
+        defuzzify_method = self.map_fcl_defuzz_method_to_skf(fcl_method)
+
+        consequent.defuzzify_method = defuzzify_method
+
     def getLinguistic_term_var_dict(self, linguistic_term_ctx):
         var_dict = None
         if hasattr(linguistic_term_ctx.parentCtx, 'ID'):

diff --git a/tests/test_listener.py b/tests/test_listener.py
@@ -441,3 +441,24 @@ def test_consequents_term_defined_if_present(self):
         self.assertEqual('consequent1', consequents.get('consequent1').get('value').label)
         self.assertIn('mf1', consequents.get('consequent1').get('value').terms)
         self.assertIn('mf1', consequents.get('consequent1').get('value').terms.get('mf1').label)
+
+    def test_consequents_defuzzify_method_cog_as_centroid(self):
+        fcl_text = """
+        FUNCTION_BLOCK my_system
+            DEFUZZIFY consequent1
+                METHOD : COG;
+            END_DEFUZZIFY
+        END_FUNCTION_BLOCK
+        """
+        lexer = FclLexer(InputStream(fcl_text))
+        stream = CommonTokenStream(lexer)
+        parser = FclParser(stream)
+        tree = parser.main()
+
+        listener = ScikitFuzzyFclListener()
+        walker = ParseTreeWalker()
+        walker.walk(listener, tree)
+        consequents = listener.consequents
+        self.assertIn('consequent1', consequents)
+        self.assertEqual('consequent1', consequents.get('consequent1').get('value').label)
+        self.assertEqual('centroid', consequents.get('consequent1').get('value').defuzzify_method)