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//disable the stl warning of debug information conflicting with names of longer than 255 char.
#pragma warning( disable :4786 )  

#include <iostream>
#include <vector>
#include "LinAlg/Matrix.h"
#include "LinAlg/Vector.h"
#include "LinAlg/LapackFunc.h"

using namespace std;
using namespace LinAlg;

int main()
{
                // Matrix row and column dimensions
                int N=4,M=4;

                // Fill the matrix with random values.
                srand(0);
                CMatrix mat(N,M,0);
                for(int i=0;i<N;++i)
                                for(int j=0;j<M;++j)
                                                mat.set(i,j,rand()/double(RAND_MAX)-0.5);

                // Create a vector of random values
                CVector b(N);
                for(int i=0;i<N;++i)
                                b.set(i, rand()/double(RAND_MAX)-0.5);
                
                // Some output
                cout << "Matrix rows, cols = "; 
                cout << mat.Rows() << " , " << mat.Cols() << endl;
                cout << "Matrix: " << mat << endl;
                cout << "Vector: " << b << endl;
                
                // Use lapack function to do least squares solution
                CVector x(M);
                x = LinearLSSolve(mat,b);
                cout << "Least squares solution: " << x << endl;
                
                // Of course if the system has full rank, we can use
                //CVector LinearSolve(const CMatrix& A,const CVector&b);

                // Manual (and less efficient least squares solution ...
                CMatrix mat_T = mat.Transposed(); 
                CMatrix mat2 = mat_T * mat;
                Invert(mat2);
                mat2 = mat2 * mat_T;

                CVector x2(M);
                x2 = mat2 * b;
                cout << "Least squares solution: " << x2 << endl;

}