package?user.cf;

import?java.io.BufferedReader;
import?java.io.File;
import?java.io.FileNotFoundException;
import?java.io.FileReader;
import?java.io.IOException;
import?java.util.ArrayList;
import?java.util.Arrays;
import?java.util.List;

public?class?Usercf?{
	
	public?static?final?int?KNEIGHBOUR?=?10;	//number?of?neighbors
	public?static?final?int?PREFROWCOUNT?=?943;	//number?of?users?in?base
	public?static?final?int?COLUMNCOUNT?=?1682;	//number?of?items
	public?static?final?int?TESTROWCOUNT?=?462;	//number?of?users?in?test
	public?static?final?String?base?=?“u1.base“;//訓練集
	public?static?final?int?base_LINE?=?80000;//base
	public?static?final?String?TEST?=?“u1.test“;//測試集
	public?static?final?int?TEST_LINE?=?20000;//test
	
	
	public?static?void?main（String[]?args）?{
		
		Usercf?cf?=?new?Usercf（）;
		
		int[][]?user_movie_base?=?cf.readFile（base_LINE?base）;?//構建訓練集數據														
		int[][]?test?=?cf.readFile（TEST_LINE?TEST）;?		???//構建測試集數據?
		
		double[][]?similarityMatrix?=?cf.produceSimilarityMatrix（user_movie_base）;//構建用戶相似性矩陣
		
		double[][]?matrix?=?cf.getScore（user_movie_base?similarityMatrix）;
		
		double[]?mae?=?cf.produceMAE（matrix?test）;
		double?Mae?=?0.0?MAE?=?0.0;
		for?（int?k?=?0;?k?			Mae?+=?mae[k];
		}
		MAE?=?Mae?/?TESTROWCOUNT;
		System.out.println（“MAE=:“?+?MAE）;
	}
	
	
	/**
	?*?完成數據讀入功能
	?*?@param?rowCount?數據行數
	?*?@param?fileName?文件名稱
	?*?@return
	?*/
	
	public?int[][]?readFile（int?rowCountString?fileName）?{	
		int?[][]?user_movie=new?int?[PREFROWCOUNT][COLUMNCOUNT];//創建用戶-項目評分矩陣
		try?{
			File?file?=?new?File（fileName）;
			FileReader?fr?=?new?FileReader（file）;
			BufferedReader?br?=?new?BufferedReader（fr）;
			String?line?=null;
//			int?i?=?0;
			while?（（line?=?br.readLine（））!=null）?{
				String[]?data?=?line.split（“\t“）;
				int[]?tempdata?=?new?int[4];?
				for?（int?j?=?0;?j?					tempdata[j]?=?Integer.parseInt（data[j]）;
					}
				user_movie[tempdata[0]-1][tempdata[1]-1]=tempdata[2];//構建用戶-項目評分數據矩陣
//				i++;
				}
			}?catch?（FileNotFoundException?e）?{
				e.printStackTrace（）;
				}?catch?（IOException?e）?{
					e.printStackTrace（）;
					}
		System.out.println（“讀入數據完成...“）;
		
		return?user_movie;??//return?preference;
		}
	

	/**
	?*?構建用戶-用戶相似性矩陣
	?*?@param?preference?用戶-項目評分矩陣
	?*?@return
	?*/
	public?double[][]?produceSimilarityMatrix（int[][]?preference）?{
		double[][]?similarityMatrix?=?new?double[PREFROWCOUNT][PREFROWCOUNT];//創建用戶-用戶相似性矩陣
		
		
		for?（int?i?=?0;?i?		for?（int?j?=?0;?j?			if?（i?==?j）?{
				similarityMatrix[i][j]?=?1;
				}
			else?{
				similarityMatrix[i][j]?=?computeSimilarity（preference[i]?preference[j]）;
				}			
			}
		}
		return?similarityMatrix;
	}

	
	/**
	?*?計算用戶之間的相似性
	?*?@param?user1
	?*?@param?user2
	?*?@return
	?*/

	public?double?computeSimilarity（int[]?user1int[]?user2）?{
		
		List

?屬性????????????大小?????日期????時間???名稱
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?????文件????????301??2016-03-14?21:09??User_CF\.classpath

?????文件????????383??2016-03-14?21:09??User_CF\.project

?????文件????????598??2016-03-14?21:09??User_CF\.settings\org.eclipse.jdt.core.prefs

?????文件???????6305??2016-03-14?21:33??User_CF\bin\user\cf\Usercf.class

?????文件???????6864??2016-03-14?21:33??User_CF\src\user\cf\Usercf.java

?????文件????1586544??2014-06-07?08:35??User_CF\u1.base

?????文件?????392629??2014-06-07?08:35??User_CF\u1.test

?????目錄??????????0??2016-03-14?21:59??User_CF\bin\user\cf

?????目錄??????????0??2016-03-14?21:59??User_CF\src\user\cf

?????目錄??????????0??2016-03-14?21:59??User_CF\bin\user

?????目錄??????????0??2016-03-14?21:59??User_CF\src\user

?????目錄??????????0??2016-03-14?21:59??User_CF\.settings

?????目錄??????????0??2016-03-14?21:59??User_CF\bin

?????目錄??????????0??2016-03-14?21:59??User_CF\src

?????目錄??????????0??2016-03-14?21:59??User_CF

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