#74 -- fix

src/main/java/ru/ulstu/extractor/rule/service/FuzzyInferenceService.java

@@ -116,7 +116,9 @@ public class FuzzyInferenceService {
         if (outputVariable != null) {
             outputVariable.defuzzify();
         }
-        return outputVariable == null ? "" : outputVariable.highestMembership(outputVariable.getValue()).getSecond().getName();
+        return (outputVariable == null || Double.isNaN(outputVariable.getValue()))
+                ? "Нет рекомендаций"
+                : outputVariable.highestMembership(outputVariable.getValue()).getSecond().getName();
         //return outputVariable == null ? "" : outputVariable.fuzzyOutputValue();
     }
 }