public FPTree CreateTree()
{
FPTree tree = new FPTree();
tree.root = new Node();
tree.arrayNode = new List <Node>(); //new Node[999999];
tree.countNode = 0;
return(tree);
}
private static FPTree CreateTree(ItemsetCollection T)
{
FPTree tree = new FPTree();
List[] list_frequencyItems_TID;
int i = 0;
list_frequencyItems_TID = ToList(T);
for (i = 0; i < T.Count; i++)
{
List list = new List();
list = list_frequencyItems_TID[i];
tree = tree.InsertNode(tree, list);
}
return(tree);
}
public FPTree InsertNode(FPTree tree, List list)
{
int i = 0;
Node root = new Node();
root = tree.root;
Node node = new Node();
node = list.pHead;
while (node != null)
{
bool flag = false;
// tìm rtrong root có itemName nào trùng với node.itemName không?
for (i = 0; i < root.nodeChildrens.Length; i++)
{
if (root.nodeChildrens[i] != null)
{
if (root.nodeChildrens[i].itemName == node.itemName)
{
flag = true;
break;
}
}
}
// nếu tìm thấy thì tăng cout của itemName đó lên 1
if (flag == true)
{
root.nodeChildrens[i].count += 1;
if (node.nodeChild != null && node.nodeChild.nodeParent != null)
{
node.nodeChild.nodeParent = root.nodeChildrens[i];
}
}
// ngược lại tạo node mới
else
{
node.nodeParent = root;
node.count += 1;
tree.countNode += 1;
// gán node là con của root
for (i = 0; i < root.nodeChildrens.Length; i++)
{
if (root.nodeChildrens[i] == null)
{
root.nodeChildrens[i] = node;
break;
}
}
tree.arrayNode.Add(node);
// thêm node vào arrayNode
//for (i = 0; i < tree.countNode; i++)
//{
// if (tree.arrayNode[i] == null)
// {
// tree.arrayNode[i] = node;
// break;
// }
//}
// link đến node có itemName giống node
//for (i = tree.countNode - 2; i > 0; i--)
//{
// if (tree.arrayNode[i] != null)
// {
// if (tree.arrayNode[i].itemName == node.itemName)
// {
// node.nodeLink = arrayNode[i];
// break;
// }
// }
//}
}
if (node.nodeChild == null)
{
root = node;
}
else
{
root = node.nodeChild.nodeParent;
}
node = node.nodeChild;
}
return(tree);
}
public static ItemsetCollection DoFPGrowthParallel(ItemsetCollection db, double supportThreshold)
{
ItemsetCollection Fre = new ItemsetCollection(); //List of Items > support
ItemsetCollection T = new ItemsetCollection(); //frequent items
List <ItemsetCollection> P = new List <ItemsetCollection>();
ItemsetCollection FPTreeCon = new ItemsetCollection(); //Conditional FP-Tree
//item > support
//Itemset I = db.GetUniqueItems();
//foreach (string item in I)
//{
// Itemset itemset = new Itemset() { item };
// itemset.Support = db.FindSupport(itemset);
// if (itemset.Support >= supportThreshold)
// {
// Fre.Add(itemset);
// }
//}
//// sort item
//Fre.Sort(delegate (Itemset x, Itemset y)
//{
// if (x.Support > y.Support) return -1;
// else if (x.Support < y.Support)
// return 1;
// else return 0;
//});
////Fre = ParallelFre(db, supportThreshold);
////frequent items
//foreach (Itemset itemdata in db)
//{
// Itemset itemset = new Itemset();
// foreach (Itemset itemFre in Fre)
// {
// if (itemdata.Contains(itemFre[0]))
// {
// itemset.Add(itemFre[0]);
// }
// }
// T.Add(itemset);
//}
T = ParallelFPGrowth(db, supportThreshold, ref Fre);
// create FP Tree
FPTree tree = CreateTree(T);
// Conditional Patern Bases
foreach (Itemset itemset in Fre)
{
ItemsetCollection itemsetCollection = new ItemsetCollection();
for (int j = 0; j < tree.countNode; j++)
{
var node = tree.arrayNode[j];
if (node.itemName.Equals(itemset[0]) && !node.visited)
{
node.visited = true;
var nodeparent = node.nodeParent;
while (nodeparent.itemName > -1)
{
int index = itemsetCollection.FindIndex(nodeparent.itemName);
if (index > -1)
{
itemsetCollection[index].Support += node.count;
}
else
{
Itemset item = new Itemset();
item.Support = node.count;
item.Add(nodeparent.itemName);
itemsetCollection.Add(item);
}
nodeparent = nodeparent.nodeParent;
}
}
}
P.Add(itemsetCollection);
}
// Conditional FP-Tree
for (int i = 0; i < P.Count; i++)
{
ItemsetCollection itemsetCollection = new ItemsetCollection();
//itemsetCollection.Add(Fre[i]); //hoán vị sau
foreach (var item in P[i])
{
if (db.Support(item) >= supportThreshold)
{
itemsetCollection.Add(item);
}
}
ItemsetCollection subsets = Bit.FindSubsets(itemsetCollection.GetUniqueItems(), 0); //get all subsets
foreach (Itemset items in subsets)
{
items.Add(Fre[i][0]);
items.Support = db.FindSupport(items);
if (items.Support >= supportThreshold)
{
FPTreeCon.Add(items);
}
}
}
return(FPTreeCon);
}