graph.java

经典人工智能源程序

import javax.swing.*;
import java.awt.*;
/**
 * Title:        Graph<p>
 * Description:  Simple program to produce a graph for the book<p>
 * Copyright:    Copyright (c) Mark Watson<p>
 * Company:      <p>
 * @author Mark Watson
 * @version 1.0
 */


public class Graph extends JFrame {
  GraphPanel jPanel1;
  float [] data1;
  float [] data2;
  public Graph() {
    try {
      int size = 500;
      data1 = new float[size];
      data2 = new float[size];
      float xmin = -5;
      float xmax = 5;
      for (int i=0; i<size; i++) {
        float x = i;
        x = xmin + x * (xmax - xmin) / (float)size;
        data1[i] = sigmoid(x);
        data2[i] = sigmoidP(x);
      }
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }

  protected float sigmoid(float x) {
    return
     (float)((1.0f/(1.0f+Math.exp((double)(-x))))-0.5f);
  }

  protected float sigmoidP(float x) {
    double z = sigmoid(x) + 0.5f;
    return (float)(z * (1.0f - z));
  }

  public static void main(String[] args) {
    Graph untitled11 = new Graph();
  }

  private void jbInit() throws Exception {
    jPanel1 = new GraphPanel(data1, data2);
    jPanel1.setBackground(Color.white);
    this.setDefaultCloseOperation(3);
    this.getContentPane().add(jPanel1, BorderLayout.CENTER);
    setSize(550, 300);
    jPanel1.setVisible(true);
    setVisible(true);
  }
}