//B1.4Thêm từng giao tác vào cây
private void InsertTransaction(List <string> aTransaction)
{
List <Item> Allitems = inputDatabaseHelper.CalculateFrequencyAllItems();
List <Item> items = new List <Item>();
//frequent items trong mỗi giao tác
for (int i = 0; i < aTransaction.Count; i++)
{
bool containsItem = frequentItems.Any(item => item.Symbol == Allitems[i].Symbol);
if (aTransaction[i].Equals("y") && containsItem)
{
items.Add(Allitems[i]);
}
}
items = items.OrderByDescending(x => x.SupportCount).ToList(); // Xong B1.2
Node tempRoot = root;
Node tempNode;
//Thêm node vào cây
foreach (Item anItem in items)
{
Node aNode = new Node(anItem.Symbol);
aNode.FpCount = 1;
if ((tempNode = tempRoot.Children.Find(c => c.Symbol == aNode.Symbol)) != null)
{
tempNode.FpCount++;
tempRoot = tempNode;
}
else
{
tempRoot.AddChild(aNode);
tempRoot = aNode;
if (headerTable.ContainsKey(aNode.Symbol)) // Table header các item phổ biến 1 hạng mục
{
aNode.NextHeader = headerTable[aNode.Symbol];
headerTable[aNode.Symbol] = aNode;
}
else
{
headerTable[aNode.Symbol] = aNode;
}
}
}
}
private void CalculateFrequentItems()
{
List <Item> items = inputDatabaseHelper.CalculateFrequencyAllItems();
foreach (Item anItem in items)
{
if (anItem.SupportCount >= minimumSupportCount)
{
frequentItems.Add(anItem.Clone());
}
}
}
//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);
}