niudun21.java

数值分析之计算方法与实验2：方程求根 by java

import java.io.*;
class Niudun21{
  static double f(double x){
    return x*Math.exp(x)-1;
  }  
  static void gexianfa(double x0,double x1,double epsion)throws IOException{
  	PrintWriter out = new PrintWriter(new FileWriter("result.txt"));
    int n;
    double x[]=new double[100];
    x[0]=x0;x[1]=x1;
    double eps=epsion;
    n=2;
    out.println("x[0]="+x[0]);
    out.println("x[1]="+x[1]);
    while(n<100){
      x[n]=x[n-1]-f(x[n-1])*(x[n-1]-x[n-2])/(f(x[n-1])-f(x[n-2]));
      out.println("x["+n+"]="+x[n]);
      if(Math.abs(x[n]-x[n-1])<eps)break;
      n++;
    }
    out.close();
  }
  public static void main(String[]args)throws IOException{
    gexianfa(0.0,1.0,0.5*Math.pow(10,-6));
  }  
}