public static ItemsetCollection FindSubsets(Itemset itemset, int n) { ItemsetCollection subsets = new ItemsetCollection(); int subsetCount = (int)Math.Pow(2, itemset.Count); for (int i = 0; i < subsetCount; i++) { if (n == 0 || GetOnCount(i, itemset.Count) == n) { string binary = DecimalToBinary(i, itemset.Count); Itemset subset = new Itemset(); for (int charIndex = 0; charIndex < binary.Length; charIndex++) { if (binary[charIndex] == '1') { subset.Add(itemset[charIndex]); } } subsets.Add(subset); } } return(subsets); }
static ItemsetCollection AprioriCalc(ItemsetCollection db, double supportThreshold) { Itemset I = db.GetUniqueItems(); ItemsetCollection LitemList = new ItemsetCollection(); ItemsetCollection PitemList = new ItemsetCollection(); foreach (string item in I) { PitemList.Add(new Itemset() { item }); } int k = 2; while (PitemList.Count != 0) { LitemList.Clear(); foreach (Itemset index in PitemList) { index.Support = db.FindSupport(index); if (index.Support >= supportThreshold) { LitemList.Add(index); itemList.Add(index); } } PitemList.Clear(); PitemList.AddRange(Bit.FindSubsets(LitemList.GetUniqueItems(), k)); //get k-item subsets k += 1; } return(itemList); }
public ItemsetCollection setData() { _items = new Itemset(); _items.Add("Game"); _items.Add("Water"); _items.Add("Monster"); _items.Add("Candy"); _items.Add("Shoes"); _items.Add("Controller"); _items.Add("PizzaRolls"); _items.Add("Console"); _db = new ItemsetCollection(); _db.Add(new Itemset() { _items[0], _items[2], _items[3], _items[5] }); _db.Add(new Itemset() { _items[1], _items[4] }); _db.Add(new Itemset() { _items[0], _items[2], _items[6] }); _db.Add(new Itemset() { _items[1], _items[3], _items[4], _items[7] }); _db.Add(new Itemset() { _items[0], _items[1], _items[6] }); return(_db); }