/// <summary> /// extension a itemset, we pick up the node's SIL, and its right borther's SIL, we do IStep and if its support bigger than minSupport /// we neet to merge the itemset of the node whit the item in the last position of the node's right brother's itemset /// then we insert the new itemset into the itemset tree with the position /// we store all the itemset in the DataSet's ItemSILDic /// </summary> /// <param name="itemsetTree"></param> /// <param name="node"></param> private void ItemsetExtension(ItemsetTree <string> itemsetTree, ItemsetNode <string> node) { var position = 0; var children = node.Parent.GetChildren; for (int i = node.Position + 1; i < children.Count; i++) { var rightBrother = children[i]; // var rightBrotherLastItem = rightBrother.Itemset.Last(); // var nodeLastItem = node.Itemset.Last(); // if (!DataSet.CMapIExtension.ContainsKey(nodeLastItem) || !DataSet.CMapIExtension[nodeLastItem].ContainsKey(rightBrotherLastItem)) // { // continue; // } var SIL = SparseIdList.IStep(node.SparseIdList, rightBrother.SparseIdList); if (SIL.Support >= DataSet.MinSupport) { var newItemset = node.Itemset.Clone(); newItemset.AddItems(rightBrother.Itemset.Last()); DataSet.GetItemSILDic().Add(newItemset.Display(), SIL); itemsetTree.AddChild(node, newItemset, SIL, position); position++; } } }