Re: addition of 2 matrix number

SamuelXiao wrote:


I've made some changes.

Prints:
true
true
Hello
6.0 8.0
10.0 12.0

import java.io.File;
import java.util.Scanner;

public class lab1 {
   public static void main(String[] args) throws Exception {

     Matric m1, m2, m3;

     // Menu
     System.out.println("(1) Add two matrices");
     System.out.println("(2) Multiply two matrices");
     System.out.println("(3) Take transpose of a matrix");
     System.out.println("(4) Display a maxtric");
     System.out.println("(5) Exit");
     System.out.println("\n");

     Scanner input = new Scanner(System.in);
     int choice = input.nextInt();

     switch (choice) {
     case 1: {
       String filename1, filename2;
       Scanner stdin = new Scanner(System.in);
       filename1 = stdin.next();
       filename2 = stdin.next();
       stdin.nextLine();
       //System.out.println(filename1 + " " + filename2);
       File file1 = new File(filename1);
       File file2 = new File(filename2);
       System.out.println(file1.exists());
       System.out.println(file2.exists());

       m1 = Matric.readfile(file1);
       m2 = Matric.readfile(file2);
       if ((m1.getCols() == m2.getCols()) &&
            (m1.getRows() == m2.getRows())) {
         System.out.println("Hello");
         m3 = Matric.add2matrices(m1, m2);
         m3.display();
       } else
         System.out.println(
           "This two files cannot operation for addition");

     }
       break;
     }
   }
}

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.nio.CharBuffer;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;

class Matric {

   final double[][] element;
   final int rows;
   final int cols;

   public Matric(int rows, int cols, double[][] data) {
     this.rows = rows;
     this.cols = cols;
     element = data;
   }

   public int getRows() {
     return rows;
   }

   public int getCols() {
     return cols;
   }

   public double[][] getData() {
     return element;
   }

   public static Matric add2matrices(Matric m1, Matric m2) {
     double[][] data = null;
     if (m1.getRows() == m2.getRows() && m1.getCols() == m2.getCols()) {
       data = new double[m1.getRows()][m1.getCols()];
       for (int i = 0; i < m1.getRows(); i++) {
         for (int j = 0; j < m1.getCols(); j++) {
           data[i][j] = m1.element[i][j] + m2.element[i][j];
         }
       }
       return new Matric(m1.getRows(), m1.getCols(), data);
     }
     return null;
   }

   public void display() {
     for (int i = 0; i < rows; i++) {
       for (int j = 0; j < cols; j++) {
         System.out.print(element[i][j] + " ");
       }
       System.out.println();
     }
   }

   public static Matric readfile(File file) {
     String fileString = null;
     try {
       FileReader fileReader = new FileReader(file);
       CharBuffer charBuffer = CharBuffer.allocate((int) file.length());
       try {
         fileReader.read(charBuffer);
         fileReader.close();
       } catch (IOException e) {
         // TODO
         e.printStackTrace();
       }
       charBuffer.flip();
       fileString = charBuffer.toString();
     } catch (FileNotFoundException e) {
       // TODO
       e.printStackTrace();
     }

     List<String> fileLines = new ArrayList<String>();
     StringTokenizer lineTokenizer =
       new StringTokenizer(fileString, "\n");
     while (lineTokenizer.hasMoreTokens()) {
       fileLines.add(lineTokenizer.nextToken());
     }

     int rows = Integer.parseInt(fileLines.get(1).substring(
         fileLines.get(1).indexOf("=") + 2));
     int cols = Integer.parseInt(fileLines.get(2).substring(
         fileLines.get(2).indexOf("=") + 2));
     double[][] data = new double[rows][cols];
     for (int idx = 3; idx < rows + 3; idx++) {
       String[] fieldStrings = fileLines.get(idx).split(" ");
       for (int iidx = 0; iidx < cols; iidx++) {
         data[idx - 3][iidx] = Double.parseDouble(fieldStrings[iidx]);
       }
     }
     if (data != null) {
       return new Matric(rows, cols, data);
     }
     return null;
   }

}