public int CreateFPTreeAndGenerateFrequentItemsets(
IInputDatabaseHelper _inputHelper, IOutputDatabaseHelper _outHelper, float minSup)
{
outputDatabaseHelper = _outHelper;
var watch = System.Diagnostics.Stopwatch.StartNew();
FPTree _fpTree = new FPTree(_inputHelper, minSup);
fpTree = _fpTree;
int totalFrequentItemSets = GenerateFrequentItemSets();
watch.Stop();
outputDatabaseHelper.WriteAggregatedResult(minSup, totalFrequentItemSets, (double)watch.ElapsedMilliseconds);
return(totalFrequentItemSets);
}
//generate frequent itemsets
public int GenerateFrequentItemSets()
{
var watch = System.Diagnostics.Stopwatch.StartNew();
List <ItemSet> previousItemSets = new List <ItemSet>(); //holds itemsets found in previous calculation
//insert the frequent 1-itemsets
List <Item> items = inputDatabaseHelper.CalculateFrequencyAllItems();
foreach (Item anItem in items)
{
if (anItem.SupportCount >= MinimumSupportCount) // if frequent
{
ItemSet anItemSet = new ItemSet();
anItemSet.AddItem(anItem);
previousItemSets.Add(anItemSet);
}
}
int itemSetLength = 1;
int totalFrequentItemSets = 0;
Console.WriteLine("generated " + itemSetLength.ToString() + "-itemset total " + previousItemSets.Count + " itemsets");
totalFrequentItemSets += previousItemSets.Count;
while (previousItemSets.Count != 0)
{
itemSetLength++;
List <ItemSet> newCandidates = GetNextCandidates(previousItemSets);
previousItemSets.Clear();
previousItemSets = GetFrequentItemSetsFromCandidates(newCandidates);
totalFrequentItemSets += previousItemSets.Count;
Console.WriteLine("generated " + itemSetLength.ToString() + "-itemset total " + previousItemSets.Count + " itemsets");
}
watch.Stop();
outputDatabaseHelper.WriteAggregatedResult(inputDatabaseHelper.DatabaseName, MinimumSupport, totalFrequentItemSets, watch.ElapsedMilliseconds);
Console.WriteLine("Aggregated Result Written to " + outputDatabaseHelper.DatabasePath);
return(totalFrequentItemSets);
}