public static List <AssociationRule> Mine(ItemsetCollection db, ItemsetCollection L, double confidenceThreshold)
{
List <AssociationRule> allRules = new List <AssociationRule>();
foreach (Itemset itemset in L)
{
ItemsetCollection subsets = Bit.FindSubsets(itemset, 0); //get all subsets
foreach (Itemset subset in subsets)
{
double confidence = (FindSupport(itemset, db) / FindSupport(subset, db)) * 100;
if (confidence >= confidenceThreshold)
{
AssociationRule rule = new AssociationRule();
rule.X.AddRange(subset);
rule.Y.AddRange(itemset.Remove(subset));
rule.Support = FindSupport(itemset, db);
rule.Confidence = confidence;
if (rule.X.Count > 0 && rule.Y.Count > 0)
{
allRules.Add(rule);
}
}
}
}
return(allRules);
}
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);
}
public static ItemsetCollection SETM(ItemsetCollection db, double supportThreshold)
{
Itemset I = db.GetUniqueItems();
ItemsetCollection L = new ItemsetCollection(); //resultant large itemsets
ItemsetCollection Ci = new ItemsetCollection(); //pruned itemset in each iteration
ItemsetCollection dbTid = new ItemsetCollection();
int j = 1;
//set Tids in itemsets
foreach (var item in db)
{
item.Tid = j;
dbTid.Add(item);
j++;
}
//first iteration (1-item itemsets)
foreach (int item in I)
{
Ci.Add(new Itemset()
{
item
});
}
//next iterations
int k = 2;
while (Ci.Count != 0)
{
foreach (Itemset itemset in Ci)
{
itemset.Support = FindSupport(itemset, Ci);
if (itemset.Support >= supportThreshold)
{
L.Add(itemset);
}
}
//set Ci for next iteration (find subsets of k of sets with Tid)
Ci.Clear();
foreach (var set in dbTid)
{
var b = Bit.FindSubsets(set, k);
foreach (var bit in b)
{
bit.Tid = set.Tid;
Ci.Add(bit);
}
}
k += 1;
}
return(L);
}
public static double FindSupport(Itemset itemset, ItemsetCollection itemsetCollection)
{
int mathCount = 0;
mathCount = (from i in itemsetCollection
where i.Contains(itemset)
select i).Count();
double support = ((double)mathCount / (double)itemsetCollection.Count()) * 100;
return(support);
}
public static ItemsetCollection Apriori(ItemsetCollection db, double supportThreshold)
{
Itemset I = db.GetUniqueItems();
ItemsetCollection L = new ItemsetCollection(); //resultant large itemsets
ItemsetCollection Li = new ItemsetCollection(); //large itemset in each iteration
ItemsetCollection Ci = new ItemsetCollection(); //pruned itemset in each iteration
//first iteration (1-item itemsets)
foreach (int item in I)
{
Ci.Add(new Itemset()
{
item
});
}
//next iterations
int k = 2;
while (Ci.Count != 0)
{
//set Li from Ci (pruning)
Li.Clear();
foreach (Itemset itemset in Ci)
{
itemset.Support = FindSupport(itemset, db);
if (itemset.Support >= supportThreshold)
{
Li.Add(itemset);
L.Add(itemset);
}
}
//set Ci for next iteration (find supersets of Li)
Ci.Clear();
Ci.AddRange(Bit.FindSubsets(Li.GetUniqueItems(), k)); //get k-item subsets
k += 1;
}
return(L);
}
public static double FindSupportCountingBase(Itemset itemset, List <ItemsetCollection> countingBase, ItemsetCollection itemsetCollection)
{
int mathCount = 0;
foreach (ItemsetCollection collection in countingBase)
{
int Count = (from i in collection
where i.Contains(itemset)
select i).Count();
mathCount += Count;
}
double support = ((double)mathCount / (double)itemsetCollection.Count()) * 100;
return(support);
}
public static ItemsetCollection AprioriTid(ItemsetCollection db, double supportThreshold)
{
Itemset I = db.GetUniqueItems();
ItemsetCollection L = new ItemsetCollection(); //resultant large itemsets
ItemsetCollection Li = new ItemsetCollection(); //large itemset in each iteration
ItemsetCollection Ci = new ItemsetCollection(); //pruned itemset in each iteration
List <ItemsetCollection> CountingBase = new List <ItemsetCollection>();
//first iteration of countingbase structure
foreach (Itemset itemset in db)
{
ItemsetCollection cbCollection = new ItemsetCollection();
CountingBase.Add(cbCollection);
foreach (int ele in itemset)
{
Itemset cbItemset = new Itemset();
cbItemset.Add(ele);
cbCollection.Add(cbItemset);
}
}
//first iteration (1-item itemsets)
foreach (int item in I)
{
Ci.Add(new Itemset()
{
item
});
}
//next iterations
int k = 2;
while (Ci.Count != 0)
{
List <ItemsetCollection> TempCountingBase = new List <ItemsetCollection>();
//set Li from Ci (pruning)
Li.Clear();
foreach (Itemset itemset in Ci)
{
itemset.Support = FindSupportCountingBase(itemset, CountingBase, db);
if (itemset.Support >= supportThreshold)
{
Li.Add(itemset);
L.Add(itemset);
}
}
//set Ci for next iteration (find supersets of Li)
Ci.Clear();
Ci.AddRange(Bit.FindSubsets(Li.GetUniqueItems(), k)); //get k-item subsets
//next itteration of countingbase structure
foreach (ItemsetCollection itemsetCollection in CountingBase)
{
ItemsetCollection CountingBaseItemsetCollection = new ItemsetCollection();
Itemset tempItemset = new Itemset();
foreach (Itemset itemset in itemsetCollection)
{
foreach (int i in itemset)
{
tempItemset.Add(i);
}
}
foreach (Itemset item in Ci)
{
if (tempItemset.Contains(item))
{
CountingBaseItemsetCollection.Add(item);
}
}
if (CountingBaseItemsetCollection.Count() > 0)
{
TempCountingBase.Add(CountingBaseItemsetCollection);
}
}
CountingBase = TempCountingBase;
k += 1;
}
return(L);
}