143 lines
3.7 KiB
Java
143 lines
3.7 KiB
Java
import java.awt.*;
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import java.util.*;
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import javax.swing.*;
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public class ForceBasedGraphDrawer extends JFrame {
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static Random rnd = new Random();
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JPanel panel;
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double[] x, y;
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public void drawGraph(int[][] d) {
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int n = d.length;
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x = new double[n];
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y = new double[n];
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Set<Long> set = new HashSet<>();
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for (int i = 0; i < n; i++) {
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while (true) {
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int px = rnd.nextInt(100);
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int py = rnd.nextInt(100);
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x[i] = px;
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y[i] = py;
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long key = px * 1000000000L + py;
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if (!set.contains(key)) {
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set.add(key);
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break;
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}
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}
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}
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double k1 = 1;
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double k2 = 100000;
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for (int step = 0; step < 500000; step++) {
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double[] fx = new double[n];
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double[] fy = new double[n];
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for (int i = 0; i < n; i++) {
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for (int j = 0; j < n; j++) {
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if (i == j) {
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continue;
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}
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double dx = x[j] - x[i];
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double dy = y[j] - y[i];
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double dist = Math.sqrt(dx * dx + dy * dy);
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dx /= dist;
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dy /= dist;
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double force = k2 / (dist * dist);
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if (d[i][j] > 0) {
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force += -k1 * (dist - 1);
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}
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fx[j] += force * dx;
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fy[j] += force * dy;
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}
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}
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for (int i = 0; i < n; i++) {
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x[i] += fx[i] / 1000;
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y[i] += fy[i] / 1000;
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}
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if (step % 100 == 0) {
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try {
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Thread.sleep(1);
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} catch (InterruptedException e) {
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}
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}
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panel.repaint();
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}
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}
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public ForceBasedGraphDrawer() {
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int n = rnd.nextInt(40) + 50;
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final int[][] d = new int[n][n];
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for (int i = 0; i + 1 < n; i++) {
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d[i][i + 1] = d[i + 1][i] = 1;
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}
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for (int i = 0; i < 2 * n; i++) {
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int u = rnd.nextInt(n - 1);
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int v = u + 1 + rnd.nextInt(n - 1 - u);
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d[u][v] = d[v][u] = 1;
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}
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// "hard" example
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// int t = 10;
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// n = 2 * t + 1;
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// final int[][] d = new int[n][n];
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// for (int i = 0; i < t; i++) {
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// d[i][(i + 1) % t] = d[(i + 1) % t][i] = 1;
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// d[i][n - 1] = d[n - 1][i] = 1;
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// d[i + t][n - 1] = d[n - 1][i + t] = 1;
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// d[i][i + t] = d[i + t][i] = 1;
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// d[i][(i + 1) % t + t] = d[(i + 1) % t + t][i] = 1;
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// }
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panel = new JPanel() {
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protected void paintComponent(Graphics g) {
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super.paintComponent(g);
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if (x == null) {
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return;
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}
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Double minx = Double.POSITIVE_INFINITY;
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Double miny = Double.POSITIVE_INFINITY;
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int n = d.length;
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for (int i = 0; i < n; i++) {
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minx = Math.min(minx, x[i]);
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miny = Math.min(miny, y[i]);
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}
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int[] x1 = new int[n];
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int[] y1 = new int[n];
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for (int i = 0; i < n; i++) {
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x1[i] = (int) (x[i] - minx) + 10;
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y1[i] = (int) (y[i] - miny) + 10;
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}
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Graphics2D g2 = ((Graphics2D) g);
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g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
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g2.setStroke(new BasicStroke(3));
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g.setColor(Color.BLUE);
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for (int i = 0; i < n; i++) {
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for (int j = 0; j < n; j++) {
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if (d[i][j] > 0) {
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g.drawLine(x1[i], y1[i], x1[j], y1[j]);
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}
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}
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}
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g.setColor(Color.RED);
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for (int i = 0; i < n; i++) {
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g.drawOval(x1[i] - 1, y1[i] - 1, 3, 3);
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}
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}
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};
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setContentPane(panel);
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new Thread() {
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public void run() {
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drawGraph(d);
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}
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}.start();
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}
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public static void main(String[] args) {
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JFrame frame = new ForceBasedGraphDrawer();
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frame.setSize(new Dimension(800, 600));
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frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
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frame.setVisible(true);
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}
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} |