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

namespace Strang3Ed.Chapter05.Section1
{
    public class ExampleA
    {
        public ExampleA()
        {
        }
        private string result;
        public string Result
        {
            get { return result; }
        }
        public void Compute()
        {
            double[,] x = {{0.0,0.0,1.0},
                           {0.0,2.0,3.0},
                           {4.0,5.0,6.0}};

            L.Matrix A = new L.Matrix(x);           
            result += A.Determinant.ToString()+"\r\n";
            result += A.ToString() + "  ";

            for (int i = 0; i < A.SizeOfRow; i++)
                for (int j = 0; j < A.SizeOfRow; j++)
                    A[i, j] = Math.Pow(-1.0, i + j) * A[i, j];
            result += A.Determinant.ToString() + "\r\n";
            result += A.ToString() + "  ";

            L.Matrix B = new L.Matrix(3, 3);
            for (int i = 0; i < A.SizeOfRow; i++)
                for (int j = 0; j < A.SizeOfRow; j++)
                {
                    double sum = 0.0;
                    for (int k = 0; k < A.SizeOfRow; k++)
                        sum += A[i, k] * A[j, k];
                    B[i, j] = sum;
                }
            result += B.Determinant.ToString() + "\r\n";
            result += B.ToString() + "  ";
        }
    }
}
/*
-8
0     0     1     
0     2     3     
4     5     6     

  -8
0     0     1     
0     2     -3     
4     -5     6     

  64
1     -3     6     
-3     13     -28     
6     -28     77     
*/