[hardwired]

Code:

jButton3.addActionListener(new SimTest(this));

From the looks of this line the error would likely say that the jvm cannot find a constructor in the SimTest class that takes an argument of the type referred to by the this keyword. If I try compiling

Code:

SimTest simTest = new SimTest("Hello World");

I get

Code:

C:\jexp>javac test.java
test.java:6: cannot find symbol
symbol  : constructor SimTest(java.lang.String)
location: class SimTest
        SimTest simTest = new SimTest("Hello World");
                          ^
1 error

The jvm cannot find a SimTest constructor that takes a String argument.
The SimTest class (post #6) has no explicit constructor so the jvm provides a default, no–argument constructor.

And how do I implement the second question ?
From the original post #1:
2. I want to insert a image to be the background of the grids, instead of that piece of white sheet, can this be done ?
or from #5
Q2. Here is where I want to insert the image.
Sorry, I forgot about the image.

Code:

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.swing.*;

public class SimTest implements ActionListener {
    BufferedImage image;
    Random seed = new Random();
    JDialog dialog;

    public SimTest(BufferedImage image) {
        this.image = image;
    }

    public void actionPerformed(ActionEvent e) {
        int[] data = getData();
        DataPanel dataPanel = new DataPanel(data, image);
        if(dialog == null) {
            dialog = new JDialog(new Frame(), "data plot", false);
            dialog.setSize(400,400);
            dialog.setLocationRelativeTo(null);
            dialog.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE);
        }
        dialog.add(dataPanel);
        dialog.setVisible(true);
    }

    private int[] getData() {
        int[] data = new int[8];
        for(int i = 0; i < data.length; i++) {
            data[i] = seed.nextInt(101);
        }
        return data;
    }

    private JPanel getContent() {
        JButton button = new JButton("test");
        button.addActionListener(this);
        JPanel panel = new JPanel(new GridBagLayout());
        panel.add(button, new GridBagConstraints());
        return panel;
    }

    public static void main(String[] args) throws IOException {
        String path = "images/hawk.jpg";
        BufferedImage image = ImageIO.read(new File(path));
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new SimTest(image).getContent());
        f.setSize(200,75);
        f.setLocation(200,200);
        f.setVisible(true);
    }
}

class DataPanel extends JPanel {
    int[] data;
    BufferedImage image;
    final int PAD = 20;

    public DataPanel(int[] data, BufferedImage image) {
        this.data = data;
        this.image = image;
    }

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        int w = getWidth();
        int h = getHeight();
        // Draw image centered.
        int x0 = (w - image.getWidth())/2;
        int y0 = (h - image.getHeight())/2;
        g2.drawImage(image, x0, y0, this);
        // Draw ordinate.
        g2.draw(new Line2D.Double(PAD, PAD, PAD, h-PAD));
        // Draw abcissa.
        g2.draw(new Line2D.Double(PAD, h-PAD, w-PAD, h-PAD));
        double xInc = (double)(w - 2*PAD)/(data.length-1);
        double scale = (double)(h - 2*PAD)/getMax();
        // Draw lines.
        g2.setPaint(Color.blue);
        for(int i = 0; i < data.length-1; i++) {
            double x1 = PAD + i*xInc;
            double y1 = h - PAD - scale*data[i];
            double x2 = PAD + (i+1)*xInc;
            double y2 = h - PAD - scale*data[i+1];
            g2.draw(new Line2D.Double(x1, y1, x2, y2));
        }
        // Mark data points.
        g2.setPaint(Color.red);
        for(int i = 0; i < data.length; i++) {
            double x = PAD + i*xInc;
            double y = h - PAD - scale*data[i];
            g2.fill(new Ellipse2D.Double(x-2, y-2, 4, 4));
        }
    }

    private int getMax() {
        int max = -Integer.MAX_VALUE;
        for(int i = 0; i < data.length; i++) {
            if(data[i] > max)
                max = data[i];
        }
        return max;
    }
}