class MatrixApplication1
{
    public static void main(String args[])
    {

	Random rand = new Random();
	int n=4;

	Matrix A1=new DenseMatrix(n,rand);

	System.out.println("Matrix A1 in Dense Format\n");
	A1.print();

        //Change Elements (3,0) (2,1) (1,2) (0,3)
	A1.set(3,0,1.0);
	A1.set(2,1,2.0);
	A1.set(1,2,3.0);
	A1.set(0,3,4.0);

	System.out.println("Matrix A1 after changes\n");
	A1.print();


	System.out.println("Print diagonal elements of A1\n");
	//// one could do
	// for (int i=0;i<A1.size();i++){System.out.println(A1.get(i,i));}
	//// However we will use the following
	double[] diag=A1.diagonal();
	for (int i=0;i<A1.size();i++){System.out.println(diag[i]);}

	// Define a vector
        Vector B=new Vector(n);
	B.set(0,1.0);
	B.set(1,0.0);
	B.set(2,0.0);
	B.set(3,0.0);
        System.out.println("Vector\n");
        B.print();
	// multiplication
        Vector F=A1.multiply(B); // F=A*B
	System.out.println("Matrix-Vector Multiplication (==first column of A1)\n");
        F.print();
    }
}