using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using L = Science.Mathematics.LinearAlgebra;

namespace Strang3Ed.Chapter06.Section4
{
    public class ExampleA
    {
        public ExampleA()
        {
        }
        private string result;
        public string Result
        {
            get { return result; }
        }
        public void Compute()
        {
            double[,] x = { {2.0, -1.0, 0.0}, 
                            {-1.0, 2.0, -1.0}, 
                            {0.0, -1.0, 2.0}};

            L.SymmetricMatrix A = new L.SymmetricMatrix(x);
            A.Diagonalize();

            result += A.Eigenvalue[0].ToString() + "\r\n";

            result += A.Eigenvector[0].ToString() + "\r\n";

            result += A.Eigenvalue[1].ToString() + "\r\n";

            result += A.Eigenvector[1].ToString() + "\r\n";

            result += A.Eigenvalue[2].ToString() + "\r\n";

            result += A.Eigenvector[2].ToString() + "\r\n";

            double[,] y = { {1.0, -1.0, 0.0, 0.0}, 
                            {-1.0, 2.0, -1.0, 0.0}, 
                            {0.0, -1.0, 2.0, -1.0}, 
                            {0.0, 0.0,-1.0, 1.0}};

            L.SymmetricMatrix B = new L.SymmetricMatrix(y);
            B.Diagonalize();

            result += B.Eigenvalue[0].ToString() + "\r\n";

            result += B.Eigenvector[0].ToString() + "\r\n";

            result += B.Eigenvalue[1].ToString() + "\r\n";

            result += B.Eigenvector[1].ToString() + "\r\n";

            result += B.Eigenvalue[2].ToString() + "\r\n";

            result += B.Eigenvector[2].ToString() + "\r\n";

            result += B.Eigenvalue[3].ToString() + "\r\n";

            result += B.Eigenvector[3].ToString() + "\r\n";
        }
    }
}
/*
3.41421356237309
0.5
-0.707106781186547
0.5

2
0.707106781186548
-2.84494650060196E-16
-0.707106781186547

0.585786437626905
0.5
0.707106781186547
0.5

3.41421356237309
-0.270598050073099
0.653281482438188
-0.653281482438188
0.270598050073099

2
-0.5
0.5
0.5
-0.5

0.585786437626905
0.653281482438188
0.270598050073098
-0.270598050073099
-0.653281482438188

-4.56365826911786E-17
-0.5
-0.5
-0.5
-0.499999999999999
*/