main.java

Algorithm of Golden Ratio Method

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package labzsechenie;

/**
 *
 * @author r_sattaruly
 */
public class Main {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        double a=-1;
        double b=1;
        double e=0.0001;
        double t=1.618;
        double x1, x2, xz;
        double f1, f2, f;
        
        x1=a+(1/(t*t))*(b-a);
        x2=a+(1/t)*(b-a);
        f1=(x1*x1-x1-1)/(x1*x1+x1+5);
        f2=(x2*x2-x2-1)/(x2*x2+x2+5);        
        
        while ((Math.abs(b-a))>e)
        {
            if(f1<f2)
            {
                b=x2;
                x2=x1;
                f2=f1;
                x1=a+(1/(t*t))*(b-a);
                f1=(x1*x1-x1-1)/(x1*x1+x1+5);
            }
            else
            {
                a=x1;
                x1=x2;
                f1=f2;
                x2=a+(1/t)*(b-a);
                f2=(x2*x2-x2-1)/(x2*x2+x2+5); 
            }                             
        }
        xz=(a+b)/2;
        f=(xz*xz-xz-1)/(xz*xz+xz+5);
        System.out.println("x* = "+xz+" f(x*) = "+f);
    }

}