class MatrixApplication2
{
    public static void main(String args[])
    {
	int n=4;
	Matrix A1=new DenseMatrix(n);
        A1.set(0,0,4.0);
        A1.set(0,3,-1.0);
        A1.set(1,1,4.0);
        A1.set(2,2,4.0);
        A1.set(3,0,-1.0);
        A1.set(3,3,4.0);
	System.out.println("Matrix A1 in dense Format\n");
	A1.print();

	Matrix A2=new SparseMatrixArray(A1);
	// change element (0,0) and (3,3)
	A2.set(0,0,2.0);
	A2.set(3,3,2.0);
	System.out.println("Print diagonal elements of A2 after changes\n");
	//// one could do
	// for (int i=0;i<A2.size();i++){System.out.println(A2.get(i,i));}
	//// However we will use the following
	double[] diag=A2.diagonal();
	for (int i=0;i<A2.size();i++){System.out.println(diag[i]);}

	// redefine A1
	A1=new DenseMatrix(A2);
	System.out.println("new Matrix A1 in dense Format\n");
	A1.print();
	// Define a vector
        Vector B=new Vector(n);
	B.set(0,1.0);
	B.set(1,1.0);
	B.set(2,1.0);
	B.set(3,1.0);
        System.out.println("Vector\n");
        B.print();
	// multiplication
        Vector F=A1.multiply(B); // F=A*B
	System.out.println("Matrix-Vector Multiplication\n");
        F.print();

    }
}