// generates candidate item set for k=2. Logic for K=2 is different as it doesnt need subset to be checked
public List <CandidateItemSet> GenerateCandidate(List <HashMap> hashitems, List <TransactionSet> hashedTransactionSet, int currentTupple, int support)
{
List <CandidateItemSet> candidateSet = new List <CandidateItemSet>();
if (hashitems.Count() != 0)
{
for (var i = 0; i <= hashitems.Count; i++)
{
for (var j = i + 1; j < hashitems.Count; j++)
{
List <int> currentTuppleList = new List <int>();
List <int> transactionList = new List <int>();
currentTuppleList.Add(hashitems[i].Order);
currentTuppleList.Add(hashitems[j].Order);
transactionList = (from list1 in hashitems[i].TransactionId
join list2 in hashitems[j].TransactionId on list1 equals list2
select list1).ToList();
if (transactionList.Count() >= support)
{
currentTuppleList.Sort();
CandidateItemSet x = new CandidateItemSet();
x.Values = new List <int>();
x.Values.AddRange(currentTuppleList);
x.Count = transactionList.Count();
x.TransactionID = transactionList;
candidateSet.Add(x);
}
}
}
}
return(candidateSet);
}
// get support count of each candidate item set at level K=3+ by traversing through whole transaction
public int GetSupportCount(CandidateItemSet candidateSet, List <TransactionSet> hashedTransactionSet, int currentTupple)
{
var currentList = hashedTransactionSet.Where(h => h.Values.Count() >= currentTupple).ToList();
int count = 0;
foreach (var t in currentList)
{
if (!candidateSet.Values.Except(t.Values).Any())
{
count++;
}
}
return(count++);
}
// generates candidate item set for k= 3+
public List <CandidateItemSet> GenerateCandidate(List <FrequentItemSet> frequentSet, List <TransactionSet> hashedTransactionSet, int currentTupple, int support)
{
List <CandidateItemSet> candidateSet = new List <CandidateItemSet>();
if (frequentSet.Count() != 0)
{
for (var i = 0; i <= frequentSet.Count; i++)
{
for (var j = i + 1; j < frequentSet.Count; j++)
{
int item1 = frequentSet[i].Values[currentTupple - 2];
int item2 = frequentSet[j].Values[currentTupple - 2];
frequentSet[i].Values.RemoveAt(currentTupple - 2);
frequentSet[j].Values.RemoveAt(currentTupple - 2);
bool contains = true;
for (int k = 0; k < currentTupple - 2; k++)
{
if (frequentSet[i].Values[k] != frequentSet[j].Values[k])
{
contains = false;
}
}
frequentSet[i].Values.Add(item1);
frequentSet[j].Values.Add(item2);
if (contains && item1 < item2)
{
List <int> currentTuppleList = new List <int>();
currentTuppleList.AddRange(frequentSet[i].Values);
currentTuppleList.Add(item2);
currentTuppleList.Sort();
if (CreateSubset(currentTuppleList, frequentSet, currentTupple))
{
currentTuppleList.Sort();
CandidateItemSet x = new CandidateItemSet();
x.Values = new List <int>();
x.Values.AddRange(currentTuppleList);
candidateSet.Add(x);
}
}
}
}
}
return(candidateSet);
}
