java - Mandelbrot集GUI java

Question

嗨，我编写了这些代码来显示曼德尔布罗集，但每次运行它时，它只显示黑色。我一直在尝试查看我的错误在哪里，但未能找到它们，因此如果你们能向我展示它们，那将会非常有帮助。

这是数字类的代码:

public class Complex {
    double real;
    double imaginary;
    public Complex(){
        real = 0;
        imaginary = 0;
    }
    public Complex(double real, double imaginary){
        this.real = real;
        this.imaginary = imaginary;
    }

    public double getReal(){
        return real;
    }
    public double getImaginary(){
        return imaginary;
    }
    public void setReal(int a){
        real = a;
    }
    public void setImaginary(int b){
        imaginary = b;
    }
    public String toString(){
        if(real == 0){
            return imaginary + "i";
        }else if(imaginary == 0){
            return real + "";
        }else if(imaginary < 0){
            return real + " - " + (-imaginary) + "i";
        }else{
            return real + " + " + imaginary + "i";
        }
    }
    public Complex square(){
        double re = real*real - imaginary*imaginary;
        double im = real*imaginary + imaginary*real;
        return new Complex(re, im);

    }
    public double modulusSquared(){
        double x = real*real;
        double y = imaginary*imaginary;
        return x + y;
    }
    public Complex add(Complex d){
        double re = real + d.real;
        double im = imaginary + d.imaginary;
        return new Complex(re, im);
    }

}

这是 GUI:

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;


public class main {

    public static void main(String[] args) {
        mandFrame frame = new mandFrame("Mandelbrot Set");
        frame.init();

    }

}
class mandFrame extends JFrame{
    Complex max = new Complex(2.0, 1.6);
    Complex min = new Complex(-2.0, -1.6);
    int iteration = 100;
    int width = 600;
    int height = 600;
    int depth = 255;
    Complex[][] dot = new Complex[width][height];
    Complex point;      //the user selected point


    public mandFrame(String title){
        super(title);
        for(int y = 0; y < height; y++){
            for(int x = 0; x < width; x++){
                dot[x][y] = toComplex(x, y);
            }
        }
    }
    void init(){
        JPanel panel1 = new JPanel();
        panel1.setLayout(new BorderLayout());
        JPanel tfPanel = new JPanel();
        tfPanel.setLayout(new FlowLayout());
        mandPanel mPanel = new mandPanel();         //show the Mandelbrot Set

        final JTextField range = new JTextField(20);        //show range of complex plane displayed
        range.setEditable(false);
        range.setText(min.real + ";" + max.real + "," + min.imaginary + ";" + max.imaginary);
        final JTextField change = new JTextField(20);       //for user to change range
        JButton set = new JButton("Set");
        set.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e){
                String s = change.getText();
                String[] parse = s.split("[;,]");
                min.real = Double.parseDouble(parse[0]);
                max.real = Double.parseDouble(parse[1]);
                min.imaginary = Double.parseDouble(parse[2]);
                max.imaginary = Double.parseDouble(parse[3]);
                range.setText(min.real + ";" + max.real + "," + min.imaginary + ";" + max.imaginary);
            }
        });
        final JTextField iter = new JTextField(10);     //let user set number of iterations
        JButton ok = new JButton("OK");             //implement number of iterations set by user
        ok.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e){
                iteration = Integer.valueOf(iter.getText());
            }
        });

        tfPanel.add(range);
        tfPanel.add(change);
        tfPanel.add(set);
        tfPanel.add(iter);
        tfPanel.add(ok);

        mPanel.addMouseListener(new MouseListener());
        mPanel.addMouseMotionListener(new MouseListener());
        panel1.add(tfPanel, BorderLayout.NORTH);
        panel1.add(mPanel, BorderLayout.CENTER);
        setContentPane(panel1);

        setSize(width, height);
        setResizable(false);

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }
    class mandPanel extends JPanel{

        public void paintComponent(Graphics g){
            super.paintComponent(g);
            for(int y = 0; y < height; y++){
                for(int x = 0; x < width; x++){
                    int it = ma(dot[x][y]);
                    g.setColor(color(it));
                    g.fillRect(x, y, 1, 1);
                }
            }
        }
    }

    Complex toComplex(int x, int y){
        Complex z = new Complex();
        z.real = min.real + ((x/width) * (max.real - min.real));    //compute               the real part of the point
        z.imaginary = max.imaginary - ((y/height) * (max.imaginary - min.imaginary));   //compute the imaginary part of the point
        return z;

    }

    public int ma(Complex z0){
        Complex z = z0;
        int it = 0;
        while((int)z.modulusSquared() < 4 && it < iteration){
            z = z.square();
            z = z.add(z0);
            it = it + 1;
        }
        return it;
    }
    public Color color(int c){
        if(c == 255){
            return Color.BLACK;
        }else{
            return new Color(0, 0, (c*3) % 254);
        }

    }
}

Answer 1

可能

z.real = min.real + ((x/width) * (max.real - min.real));

x 和 width 是 int，不是 double，尝试强制转换为 double

z.real = min.real + (( (double)x/(double)width) * (max.real - min.real));

您还应该使用Apache complex

你可以看看我做的另一个实现here使用javaFX