IFTS now heritages from WHOFTS

pyFTS/models/hofts.py

@@ -66,8 +66,35 @@ class WeightedHighOrderFLRG(flrg.FLRG):
         return self.w
 
     def get_midpoint(self, sets):
+        if self.midpoint is None:
             mp = np.array([sets[c].centroid for c in self.RHS.keys()])
-        return mp.dot(self.weights())
+            self.midpoint = mp.dot(self.weights())
+
+        return self.midpoint
+
+    def get_lower(self, sets):
+        """
+        Returns the lower bound value for the RHS fuzzy sets
+
+        :param sets: fuzzy sets
+        :return: lower bound value
+        """
+        if self.lower is None:
+            lw = np.array([sets[s].lower for s in self.RHS.keys()])
+            self.lower = lw.dot(self.weights())
+        return self.lower
+
+    def get_upper(self, sets):
+        """
+        Returns the upper bound value for the RHS fuzzy sets
+
+        :param sets: fuzzy sets
+        :return: upper bound value
+        """
+        if self.upper is None:
+            up = np.array([sets[s].upper for s in self.RHS.keys()])
+            self.upper = up.dot(self.weights())
+        return self.upper
 
     def __str__(self):
         _str = ""

pyFTS/models/ifts.py

@@ -13,7 +13,7 @@ from pyFTS.common import FuzzySet, FLR, fts, tree
 from pyFTS.models import hofts
 
 
-class IntervalFTS(hofts.HighOrderFTS):
+class IntervalFTS(hofts.WeightedHighOrderFTS):
     """
     High Order Interval Fuzzy Time Series
     """
@@ -43,9 +43,9 @@ class IntervalFTS(hofts.HighOrderFTS):
         if len(flrg.LHS) > 0:
             if flrg.get_key() in self.flrgs:
                 tmp = self.flrgs[flrg.get_key()]
-                ret = tmp.get_lower(self.sets)
+                ret = tmp.get_lower(self.partitioner.sets)
             else:
-                ret = self.sets[flrg.LHS[-1]].lower
+                ret = self.partitioner.sets[flrg.LHS[-1]].lower
         return ret
 
     def get_sequence_membership(self, data, fuzzySets):