Question

我有一个txt文件语料库，我想要计算他们的Tfidf值。我想我必须将文件标记为单词作为第一步，然后计算权重。我需要这个程序的输出是一个矩阵，其中行将是文件，列将是单词，而remaning矩阵单元格将是Tfidf值。

我被困在矩阵部分。这是我的尝试

 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.List;


public class DocumentParser {

//This variable will hold all terms of each document in an array.
private List<String[]> termsDocsArray = new ArrayList<String[]>();
private List<String> allTerms = new ArrayList<String>(); //to hold all terms
private List<double[]> tfidfDocsVector = new ArrayList<double[]>();
private List fileNameList = new ArrayList();
private File[] allfiles;
private StringBuilder sb;
private BufferedReader in = null;

/**
 * Method to read files and store in array.
 * @param filePath : source file path
 * @throws FileNotFoundException
 * @throws IOException
 */

public void parseFiles(String filePath) throws FileNotFoundException, IOException {
    allfiles = new File(filePath).listFiles();
    for (File f : allfiles) {
        if (f.getName().endsWith(".txt")) {
            fileNameList.add(f.getName());
            in = new BufferedReader(new FileReader(f));
            sb = new StringBuilder();
            String s = null;
            while ((s = in.readLine()) != null) {
                sb.append(s);
            }
            String[] tokenizedTerms = sb.toString().replaceAll("[\\W&&[^\\s]]", "").split("\\W+");   //to get individual terms
            for (String term : tokenizedTerms) {
                if (!allTerms.contains(term)) {  //avoid duplicate entry
                    allTerms.add(term);
                }
            }
            termsDocsArray.add(tokenizedTerms);
        }
    }

}

/**
 * Method to create termVector according to its tfidf score.
 * @return 
 */
public double tfIdfCalculator(String file, String word) {
    double tf; //term frequency
    double idf; //inverse document frequency
    double tfidf = 0; //term requency inverse document frequency        
    for (String[] docTermsArray : termsDocsArray) {
        double[] tfidfvectors = new double[allTerms.size()];
        int count = 0;
        for (String terms : allTerms) {
            tf = new TfIdf().tfCalculator(docTermsArray, terms);
            idf = new TfIdf().idfCalculator(termsDocsArray, terms);
            tfidf = tf * idf;
            System.out.println(terms+"\t" + tfidf);
            tfidfvectors[count] = tfidf;
            count++;


        }
        tfidfDocsVector.add(tfidfvectors);  //storing document vectors;            
    }

    return tfidf;
}


public void TfIdfMatrix() throws IOException {

    int r=allTerms.size();
    int c=tfidfDocsVector.size();

    String mat[][]= new String [r][c];

    int rNumber=0;

    for (int i = 0; i < fileNameList.size(); i++) {

        rNumber++;

        mat[rNumber][0]=(String) fileNameList.get(i);

        }

     String s;
     while ((s = in.readLine()) != null) {

         rNumber++;

         mat[0][rNumber]=s;

     }


        //System.out.print(mat);

     for (int row = 1; row <= rNumber; row++){  
         for (int col = 1; col <= rNumber; col++){
             double ifidfValue=tfIdfCalculator(mat[0][col], mat[row][0]); 
             mat[row][col]=Double.toString(ifidfValue);

              System.out.print(mat[row][col]);
         }
         }      
}

}

请帮助!!

Answer 1

这是我正在使用的代码示例。

public void tfIdfCalculator() {
            double tf; //term frequency
            double idf; //inverse document frequency
            double tfidf; //term requency inverse document frequency  

            for (String[] docTermsArray : termsDocsArray) {
                double[] tfidfvectors = new double[allTerms.size()];
                int count = 0;
                for (String terms : allTerms) {
                    tf = new TfIdf().tfCalculator(docTermsArray, terms);
                    idf = new TfIdf().idfCalculator(termsDocsArray, terms);
                    tfidf = tf * idf;
                    tfidfvectors[count] = tfidf;
                    count++;
                }
                tfidfDocsVector.add(tfidfvectors);  //storing document vectors;            
            }
        }

java中的Tfidf计算和矩阵存储

1 个答案: