integral1.java

数值算法例子,牛顿插值,拉格朗日,三次样条

/*@author 邱宇峰 ,software project031,
 *2004,11,8
 */
import java.awt.*;
class integral1{
	void calculate(Graphics g,TextField tf){
		double X,Y;
		int x=0;
		g.setColor(Color.black);
		g.drawLine(80,300,750,300);
		g.drawLine(90,150,90,300);
		g.drawString("0",90,310);
		g.drawString("6",690,310);
		g.drawString("Processing...",50,100);
		for(X=0;X<6;X+=0.01){
			Y=Math.sin(X);
			Y=100*(Y/X);
			g.drawString(".",90+x,300-(int)Y);
			x++;
		}
		int n=1;
		double a=0.0,b=6.00,e=0.0001,T0,T1,h;
		h=b-a;
		T0=(h/2)*(1+(Math.sin(b)/b));
		T1=T0/2+(h/2)*Math.abs(Math.sin(a+(h/2))/(a+(h/2)));
		while(Math.abs(T1-T0)>e){
			h=h/2;
			n=2*n;
			T0=T1;
			T1=0;
			for(int k=1;k<=n;k++){
				T1=T1+Math.abs(Math.sin(a+(k-0.5)*h)/(a+(k-0.5)*h));
				for(int i=0;i<500000;i++);
				g.setColor(Color.blue);
				g.drawLine(90+(int)((a+(k-0.5)*h)*100),300,90+(int)((a+(k-0.5)*h)*100),300-(int)(100*Math.sin((a+(k-0.5)*h))/(a+(k-0.5)*h)));
			}
			T1=T0/2+h*T1/2;
			tf.setText(""+T1);
		}
		g.drawString("End",150,100);
	}
}