Merge pull request #97 from JDWarner/sparse_system_quickfix

DOC: Make system too sparse error more informative.
scikit-fuzzy · Apr 5, 2016 · eb15e4c · eb15e4c
2 parents 62666f8 + 2dbb4bf
commit eb15e4c
Showing 1 changed file with 9 additions and 1 deletion.
diff --git a/skfuzzy/control/controlsystem.py b/skfuzzy/control/controlsystem.py
@@ -402,7 +402,15 @@ def defuzz(self):
             raise ValueError("No terms have memberships.  Make sure you "
                              "have at least one rule connected to this "
                              "variable and have run the rules calculation.")
-        return defuzz(self.var.universe, output_mf, self.var.defuzzify_method)
+        try:
+            return defuzz(self.var.universe, output_mf,
+                          self.var.defuzzify_method)
+        except AssertionError:
+            raise ValueError("Crisp output cannot be calculated, likely "
+                             "because the system is too sparse. Check to "
+                             "make sure this set of input values will "
+                             "activate at least one connected Term in each "
+                             "Antecedent via the current set of Rules.")
 
     def fuzz(self, value):
         """