/* public static void readMovieName()
* {
* StreamReader rs = new StreamReader("u.item", Encoding.Default);
* string sLine = "";
* int count = 0;
*
* while (sLine != null)
* {
* sLine = rs.ReadLine();
* if (sLine == null)
* break;
*
* int start = sLine.IndexOf('|') + 1;
* int end = sLine.IndexOf('(');
* if (end > start)
* {
* string name = sLine.Substring(start, end - start);
* if (name.EndsWith("The "))
* {
* Console.WriteLine("yes");
* name = "The " + name.Substring(0, name.Length - 6);
*
* }
* movieNames[count++] = name;
* }
* else
* {
* movieNames[count++] = "unknown";
* }
*
* }
* }*/
public int CompareTo(object other)
{
AssociationRule otherTemperature = other as AssociationRule;
if (this.Reco_degrees == otherTemperature.Reco_degrees)
{
return(0);
}
if (this.Reco_degrees < otherTemperature.Reco_degrees)
{
return(1);
}
return(-1);
}
/// <summary>
/// 获得目标用户支持的关联规则
/// </summary>
/// <param name="itemid">目标用户的用户id</param>
/// <returns>按照关联度排序后的关联规则集合</returns>
public static AssociationRule[] getSupport_AssRules(int userid)
{
// 存储该用户支持的关联规则
ArrayList support_AssocRules = new ArrayList();
AssociationRule temp_AR;
int count_id = 0;
// 用户评价过且喜欢的项目id数组
int[] love_items_id = sourceUsers[userid].getUserLoveItems_id();
// 循环搜索关联规则库
for (int i = 0; i < association_Rules.Count; i++)
{
temp_AR = (AssociationRule)association_Rules[i];
int first_itemid = temp_AR._itemid_1;
int second_itemid = temp_AR._itemid_2;
// 该用户喜欢的项目出现在该关联规则的左部
// && 该用户对规则右部项目未评分
if ((love_items_id.Contains(first_itemid)) && (sourceUsers[userid].Ratings[second_itemid] == 0))
{
support_AssocRules.Add(temp_AR);
}
}
// 按照关联度对其所支持的关联规则排序
AssociationRule[] assRules = new AssociationRule[support_AssocRules.Count];
int count = 0;
foreach (AssociationRule obj in support_AssocRules)
{
assRules[count++] = obj;
}
Array.Sort(assRules);
return(assRules);
}
/// <summary>
/// 生成关联规则
/// </summary>
public void genAssoc_rules()
{
AssociationRule obj_tempAR;
float total_confidence = 0;
ArrayList temp_AR = new ArrayList();
for (int count_ar = 0; count_ar < freq_itemsets.Count; count_ar++)
{
Frequent_Itemset obj = (Frequent_Itemset)freq_itemsets[count_ar];
int first_id = obj._itemid_1; // 第一个项目id
int second_id = obj._itemid_2; // 第二个项目id
float confidence_1 = (float)((float)obj.support_count / (float)getSupport_count(first_id)); // 置信度1
total_confidence += confidence_1;
obj_tempAR = new AssociationRule(first_id, second_id, obj.Support, confidence_1);
temp_AR.Add(obj_tempAR);
float confidence_2 = (float)((float)obj.support_count / (float)getSupport_count(second_id)); // 置信度2
total_confidence += confidence_2;
obj_tempAR = new AssociationRule(second_id, first_id, obj.Support, confidence_2);
temp_AR.Add(obj_tempAR);
}
// 置信度阈值，取平均值
float min_confidence = (float)total_confidence / (float)temp_AR.Count;
AssociationRule.min_confidence = min_confidence;
// 生成关联规则
foreach (AssociationRule obj in temp_AR)
{
if (obj.confidence > min_confidence)
{
association_Rules.Add(obj);
}
}
}
/// <summary>
/// 根据用户支持的关联规则得到依据推荐度排序的推荐项目
/// </summary>
/// <param name="Supp_AssRules">用户所支持的关联规则集合</param>
/// <param name="userid">用户id</param>
/// <returns>推荐项目id&推荐度</returns>
public static RecItemid_Degree[] getRecItems(AssociationRule[] Supp_AssRules, int userid)
{
// 每个项目的推荐度
RecItemid_Degree[] temp_recDegree = new RecItemid_Degree[sourceUsers[userid].Ratings.Length];
int count_non_zero = 1;
for (int ItemID = 1; ItemID < sourceUsers[userid].Ratings.Length; ItemID++)
{
temp_recDegree[ItemID] = new RecItemid_Degree();
temp_recDegree[ItemID].recItems_id = ItemID;
temp_recDegree[ItemID].rec_Degree = 0; // 项目推荐度初始为零
// 循环扫描关联规则集，积累项目推荐度
for (int count_AR = 0; count_AR < Supp_AssRules.Length; count_AR++)
{
if (Supp_AssRules[count_AR]._itemid_2 == ItemID)
{
temp_recDegree[ItemID].rec_Degree += Supp_AssRules[count_AR].Reco_degrees;
}
}
if(temp_recDegree[ItemID].rec_Degree != 0)
{
count_non_zero++;
}
}
// 依据推荐度排序
Array.Sort(temp_recDegree);
recItems = new RecItemid_Degree[count_non_zero];
// 得到推荐度不为零的项，返回之
for (int count_rd = 1; count_rd < recItems.Length; count_rd ++ )
{
recItems[count_rd] = temp_recDegree[count_rd];
}
return recItems;
}
/// <summary>
/// 生成关联规则
/// </summary>
public void genAssoc_rules()
{
AssociationRule obj_tempAR;
float total_confidence = 0;
ArrayList temp_AR = new ArrayList();
for (int count_ar = 0; count_ar < freq_itemsets.Count; count_ar++)
{
Frequent_Itemset obj = (Frequent_Itemset)freq_itemsets[count_ar];
int first_id = obj._itemid_1; // 第一个项目id
int second_id = obj._itemid_2; // 第二个项目id
float confidence_1 = (float)((float)obj.support_count / (float)getSupport_count(first_id)); // 置信度1
total_confidence += confidence_1;
obj_tempAR = new AssociationRule(first_id, second_id, obj.Support, confidence_1);
temp_AR.Add(obj_tempAR);
float confidence_2 = (float)((float)obj.support_count / (float)getSupport_count(second_id)); // 置信度2
total_confidence += confidence_2;
obj_tempAR = new AssociationRule(second_id, first_id, obj.Support, confidence_2);
temp_AR.Add(obj_tempAR);
}
// 置信度阈值，取平均值
float min_confidence = (float)total_confidence / (float)temp_AR.Count;
AssociationRule.min_confidence = min_confidence;
// 生成关联规则
foreach (AssociationRule obj in temp_AR)
{
if (obj.confidence > min_confidence)
association_Rules.Add(obj);
}
}
/// <summary>
/// 获得目标用户支持的关联规则
/// </summary>
/// <param name="itemid">目标用户的用户id</param>
/// <returns>按照关联度排序后的关联规则集合</returns>
public static AssociationRule[] getSupport_AssRules(int userid)
{
// 存储该用户支持的关联规则
ArrayList support_AssocRules = new ArrayList();
AssociationRule temp_AR;
int count_id = 0;
// 用户评价过且喜欢的项目id数组
int[] love_items_id = sourceUsers[userid].getUserLoveItems_id();
// 循环搜索关联规则库
for (int i = 0; i < association_Rules.Count; i++)
{
temp_AR = (AssociationRule)association_Rules[i];
int first_itemid = temp_AR._itemid_1;
int second_itemid = temp_AR._itemid_2;
// 该用户喜欢的项目出现在该关联规则的左部
// && 该用户对规则右部项目未评分
if( (love_items_id.Contains(first_itemid)) && (sourceUsers[userid].Ratings[second_itemid] == 0) )
{
support_AssocRules.Add(temp_AR);
}
}
// 按照关联度对其所支持的关联规则排序
AssociationRule[] assRules = new AssociationRule[support_AssocRules.Count];
int count = 0;
foreach (AssociationRule obj in support_AssocRules)
{
assRules[count++] = obj;
}
Array.Sort(assRules);
return assRules;
}