kyoubun - 経済統計練習帳

package ml;
 
import org.apache.commons.math3.stat.correlation.Covariance;
import org.apache.commons.math3.linear.*;
 
public class pro {
 
    RealMatrix mat;
 
    public static void main(String[] args) {
       pro test=new pro();
    }
 
    pro(){
 
 
        double x;
        double mu,sig;
 
        mu=2;
        sig=1;
        x=2.1;
 
        System.out.println(f(x,mu,sig));
 
        double[][] x1=new double[5][2];
        double[][] y1=new double[2][2];
 
        int s;
 
        for(s=0;s<5;s++){
        x1[s][0]=Math.random();
        x1[s][1]=Math.random();
        }
 
 
        Covariance v=new Covariance(x1);
        mat= v.getCovarianceMatrix();
 
        y1=mat.getData();
 
        System.out.println(y1[0][1]);
 
 
 
 
    }
double f(double x,double mu,double sig){
double pi,f1,f2;
 
        pi=Math.PI;
 
        f2=Math.sqrt(2*pi*sig*sig);
        f1=-(x-mu)*(x-mu)/(2*sig*sig);
 
        return Math.exp(f1)/f2;
}
}