/// <summary>
/// ������е�ģʽ
/// ��ȡ�Ӽ��㷨
/// </summary>
/// <param name="_treeNodeItemList"></param>
public void CombineNodes(FPTree _fpTree, List<ItemSet> _itemSetList)
{
//��ȡ���н��
List<TreeNodeItem> _treeNodeItemList = new List<TreeNodeItem>();
TreeNodeItem _treeNodeItem = _fpTree.TopNode;
bool _hasNext = (_treeNodeItem.Nodes.Count > 0);
_treeNodeItem = _treeNodeItem.Nodes[0];
while (_hasNext)
{
_treeNodeItemList.Add(_treeNodeItem);
if (_treeNodeItem.Nodes.Count > 0)
_treeNodeItem = _treeNodeItem.Nodes[0];
else
_hasNext = false;
}
int _length = _treeNodeItemList.Count;
//��1��ʼ,��Ϊ��ȡ�ռ�
for (int i = 1; i < Math.Pow(2, _length); i++)
{
String str = Convert.ToString(int.Parse(i.ToString()), 2);
str = str.PadLeft(_length, '0');
char[] _arrChr = str.ToCharArray();
ItemSet _itemSet = new ItemSet();
for (int j = _arrChr.Length-1; j >-1; j--)
{
if (_arrChr[j] == '1')
{
_itemSet.Content.Add(_treeNodeItemList[j].ItemName);
if (_itemSet.Count == 0)
_itemSet.Count = _treeNodeItemList[j].Count;
else
{
//֧�ֶȵ��ڦ��н����С��֧�ֶȼ���
if(_treeNodeItemList[j].Count < _itemSet.Count)
_itemSet.Count = _treeNodeItemList[j].Count;
}
}
}
if(_itemSet.Content.Count!=0)
_itemSetList.Add(_itemSet);
}
}
/// <summary>
/// ��Ƶ��һ�����,�Ӻ�ǰ����
/// ��������FPTree
/// </summary>
/// <param name="_frequentItemList"></param>
public void FPGrowth(FPTree _fpTree, List<TreeNodeItem> _itemSet)
{
if (_fpTree.SinglePath)
{
//�����������,��_itemSetList����
List<ItemSet> _itemSetList = new List<ItemSet>();
CombineNodes(_fpTree, _itemSetList);
//����ģʽ �¡Ȧ�,_itemSetList�Ǧµļ���
AddPattern(_itemSet, _itemSetList);
_itemSet.Clear();
}
else
{
for (int i = _fpTree.FrequentItemCount - 1; i > -1; i--)
{
//ͷ���е�ÿ��a(i)
TreeNodeItem _treeNodeItem = _fpTree.GetLinkNode(i);
//����ģʽ�� = a(i)�Ȧ�
List<TreeNodeItem> _itemSetConbine = new List<TreeNodeItem>();
if (_treeNodeItem != null)
{
if (_itemSet == null)
_itemSet = new List<TreeNodeItem>();
TreeNodeItem[] _arrTreeNodeItem = new TreeNodeItem[_itemSet.Count];
_itemSet.CopyTo(_arrTreeNodeItem);
_itemSetConbine.AddRange(_arrTreeNodeItem);
_itemSetConbine.Insert(0,_treeNodeItem);
}
//��������FPTree(1)
FPTree _conditionFPTree = new FPTree();
_conditionFPTree.MinSupCount = _fpTree.MinSupCount;
List<List<TreeNodeItem>> _listStrList = new List<List<TreeNodeItem>>();
Hashtable _hashTable = new Hashtable();
bool _doLoop = (_treeNodeItem != null);
while (_doLoop)
{
//��������ģʽ��,֧�ֶȼ�����С�������List
List<TreeNodeItem> _treeNodeItemList = new List<TreeNodeItem>();
GetParentPath(_treeNodeItem.CloneNode(), _treeNodeItemList, _hashTable, _conditionFPTree);
//���ģʽ�Ѿ��������Ҳ���Ƶ��һ�
if (_treeNodeItemList.Count == 0 && _itemSetConbine.Count >1)
//����ģʽ
AddPattern(_itemSetConbine,_fpTree);
//��������FPTree(2)
if(_treeNodeItemList.Count>0)
_listStrList.Add(_treeNodeItemList);
//�������ģʽ��
if (_treeNodeItem.NextNode != null)
_treeNodeItem = _treeNodeItem.NextNode;
else
_doLoop = false;
}
//��������FPTree(3)
if(_listStrList.Count >0)
_conditionFPTree.InitializeConditionFPTree(_listStrList);
//������Ƿ�Ϊ��
if (_conditionFPTree.TopNode.Nodes.Count > 0)
FPGrowth(_conditionFPTree, _itemSetConbine);
else
_itemSetConbine = _itemSet;
}
}
}
/// <summary>
/// ��Ϊ��ʱ����ģʽ
/// </summary>
/// <param name="_itemSetConbine">����Ħ� = a(i)�Ȧ�</param>
private void AddPattern(List<TreeNodeItem> _itemSetConbine,FPTree _fpTree)
{
//����ģʽ
if (!_frequentPattern.ContainsKey(_itemSetConbine.Count))
{
List<ItemSet> _tmpItemSetList = new List<ItemSet>();
ItemSet _tmpItemSet = new ItemSet();
//����ģʽ
foreach (TreeNodeItem _nodes in _itemSetConbine)
{
_tmpItemSet.Content.Add(_nodes.ItemName);
}
_tmpItemSet.Count =
_fpTree.GetSupCountByID(
_itemSetConbine[0].ItemName);
_tmpItemSetList.Add(_tmpItemSet);
_frequentPattern.Add(_itemSetConbine.Count, _tmpItemSetList);
}
else
{
List<ItemSet> _tmpItemSetList = (List<ItemSet>)_frequentPattern[_itemSetConbine.Count];
ItemSet _tmpItemSet = new ItemSet();
//����/���������
foreach (TreeNodeItem _nodes in _itemSetConbine)
{
_tmpItemSet.Content.Add(_nodes.ItemName);
}
_tmpItemSet.Count =
_fpTree.GetSupCountByID(
_itemSetConbine[0].ItemName);
_tmpItemSetList.Add(_tmpItemSet);
//_frequentPattern[_itemSetConbine.Count] = _tmpItemSetList;
}
}
/// <summary>
/// ����һ�������ӽڵ�ĸ����
/// ���ø����ļ���ΪҶ�ӽ�����
/// ������
/// </summary>
/// <param name="_treeNodeItem"></param>
/// <param name="_treeNodeItemList"></param>
public void GetParentPath(TreeNodeItem _treeNodeItem, List<TreeNodeItem> _treeNodeItemList, Hashtable _hashTable,FPTree _fpTree)
{
while (_treeNodeItem.Parent != null && _treeNodeItem.Parent.ItemName != null)
{
//����ģʽ�����еĽڵ��֧�ֶȼ�����ΪҶ�Ӽ���
TreeNodeItem _newTreeNodeItem = _treeNodeItem.Parent.CloneNode();
_newTreeNodeItem.Count = _treeNodeItem.Count;
_treeNodeItemList.Insert(0, _newTreeNodeItem);
//����Ƶ��һ�
if (_hashTable.ContainsKey(_newTreeNodeItem.ItemName))
_hashTable[_newTreeNodeItem.ItemName] = Convert.ToInt32(_hashTable[_newTreeNodeItem.ItemName]) +
_newTreeNodeItem.Count;
else
_hashTable.Add(_newTreeNodeItem.ItemName, _newTreeNodeItem.Count);
//Ƶ��
if (Convert.ToInt32(_hashTable[_newTreeNodeItem.ItemName]) > _fpTree.MinSupCount - 1)
{
_fpTree.BuildFrequentItemList(_newTreeNodeItem.ItemName,
Convert.ToInt32(_hashTable[_newTreeNodeItem.ItemName]));
}
_treeNodeItem = _newTreeNodeItem;
}
}
