ch6_1_2.java

来自「Java环境下实现的数值分析程序」· Java 代码 · 共 33 行

class ch6_1_2{
  public static double Function(double x){
	  return Math.exp(-Math.pow(x,2));
  }
  
  public static void EX(double a,double b){
	double l=b-a;
	double T[]=new double[32];
        double S[]=new double[32];
	double C[]=new double[32];
	double R[]=new double[32];
	for(int i=0;i<16;i++){
		T[i]=0;S[i]=0;C[i]=0;R[i]=0;
	}
	double sum=0;
	int j=1;
	do{
		for(int k=0;k<(int)(Math.pow(2,j-1));k++)
		    sum=sum+l/Math.pow(2,j)*Function(l/Math.pow(2,j)*(2*k+1));
		T[j]=T[j-1]/2+sum;
		S[j]=(4*T[j]-T[j-1])/3;
		if(j>=2) C[j]=(16*S[j]-S[j-1])/15;
		if(j>=3) R[j]=(64*C[j]-C[j-1])/63;
		j++;
		sum=0;
	}while(((Math.abs(R[j-1]-R[j-2])>0.0000005)&(j>3))||(j<=3));
	System.out.println("R["+(j-1)+"]="+R[j-1]);
  }
  
  public static void main(String[]args){
    EX(0,0.8);
  }
}