q.java

函数插值计算 分别输入已知节点的x,y值

import java.util.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
public class q extends Applet implements ActionListener
{
     Button button;
    Label l3,l4,l5,l6;
     TextField Xi,Yi,T,result;
     double x[]=new double[10];
     double y[]=new double[10]; 
     double t=0;  
 
    String s1,s2,s3;int n=0;

 public  void init ()
 {
  //l1=new Label("请在下面的对应文本框中输入数字字符以逗号或者空格分隔;"+"\n"); 
  //l2=new Label("输入完毕后按回车键,查看结果按插值botton"+"\n");
  l3=new Label("xi：");
  l4=new Label("yi：");
  l5=new Label("x：");
  //l6=new Label("插值结果是：");
  button=new Button("插值");
  Xi=new TextField(20);
  Yi=new TextField(20);
   T=new TextField(20);
   result=new TextField(10);
    
    add(l3);add(Xi);  add(l4);add(Yi); add(l5); add(T);
   //add(l6);
   add(result);add(button);
  Xi.addActionListener(this);  
  Yi.addActionListener(this);  
  T.addActionListener(this);
  button.addActionListener(this);

  }
public void paint(Graphics g)
{
  g.drawString("请在下面的对应文本框中输入数字字符",10,150);
   g.drawString("以逗号或者空格分隔",10,170);
  g.drawString("输入完毕后按回车键,查看结果按插值",10,190);
}
 public void actionPerformed(ActionEvent e)

  { 

  if(e.getSource()==Xi)
   {  int n1=0; 
      s1=Xi.getText();
      
      StringTokenizer fenxi=new StringTokenizer(s1," ,");  n=fenxi.countTokens();
     while(fenxi.hasMoreTokens())
    {
      String temp=fenxi.nextToken();
        x[n1]=Double.valueOf(temp).doubleValue();n1++;
     } 
  
 
   }
  else if(e.getSource()==Yi)
   {
     int n2=0;
      s2=Yi.getText();
      StringTokenizer fenxi=new StringTokenizer(s2," ,"); 
     while(fenxi.hasMoreTokens())
    {
      String temp=fenxi.nextToken();
        y[n2]=Double.valueOf(temp).doubleValue();n2++;
     } 
  }
 else if(e.getSource()==T)
   {
     s3=e.getActionCommand();
    t=Double.valueOf(s3).doubleValue();
   }
else if(e.getSource()==button)
 {  double pp=0,m1,m2;int i,k;
   for(i=0;i<n;i++)
   {
        m1=1;m2=1;
        for(k=0;k<n;k++)
          if(k!=i)
          {m1*=t-x[k];
           m2*=x[i]-x[k];}
          pp+=y[i]*m1/m2;
   }
result.setText(""+pp);  
 
 }
}
}