为什么我的 java 程序没有返回任何东西？

Question

For some reason, I don't get an output with the main method when I try to run the convolution2d program. What am I doing wrong here? The program is supposed to look at the convolution 2d method in another file and return it in the next one.

import java.applet.*;
import java.awt.*;
import java.awt.image.*;
import java.net.*;
import java.util.*;
import java.io.*;
import java.lang.Math.*;
import java.awt.Color.*;

/**
 * Convolution is the code for applying the convolution operator.
 */
public class convolution {

  //convolution 2d program

public static double [][] convolution2D(double [][] input,
                      int width, int height, 
                      double [][] kernel, 
                      int kernelWidth,
                      int kernelHeight){
  int smallWidth = width - kernelWidth + 1;
  int smallHeight = height - kernelHeight + 1; 
  double [][] output = new double [smallWidth][smallHeight];
  for(int i=0;i<smallWidth;++i){
    for(int j=0;j<smallHeight;++j){
output[i][j]=0;
    }
  }
  for(int i=0;i<smallWidth;++i){
    for(int j=0;j<smallHeight;++j){
output[i][j] = singlePixelConvolution(input,i,j,kernel,
                kernelWidth,kernelHeight);
//if (i==32- kernelWidth + 1 && j==100- kernelHeight + 1) System.out.println("Convolve2D: "+output[i][j]);
      }
    }
    return output;
  }



//main program

public class driverconv {

  public static void main(String[] args) {
    // TODO Auto-generated method stub
    convolution ce = new convolution();
    double[][] m1= {{1,2},{3,4}};
    double[][] m2= {{1,1},{1,1}};


    System.out.println(convolution.convolution2D(m1, 2, 2, m2, 2, 2));

  }

}

Answer 1

System.out.println() cannot print an array. If you want to print the values of the array you should create a String first (with a for loop you can iterate the array and construct the string)