Least Square Method

 //=====================Extended Leas Squire Method =========================	 	
 // Define variables	 	
    sum_x = 0;	 	
    sum_y = 0;	 	
    sum_xy = 0;
    sum_x2 = 0; 	
    sum_y2 = 0;
	 		 	
 // Length section		
    n = sections[i][1] - sections[i][0];	 
    for(int j = 0; j < n1 ;j++)
    {	 	
        // Get x,y,xy,x^2 and y^2 from all coordinates		
        sum_x += Coordinates[sections[i][0]+j][0];	 
        sum_y += Coordinates[sections[i][0]+j][1];	 
        sum_xy += Coordinates[sections[i][0]+j][0]*Coordinates[sections[i][0]+j][1];	 	
        sum_x2 += pow(Coordinates[sections[i][0]+j][0],2);	 	
        sum_y2 += pow(Coordinates[sections[i][0]+j][1],2);		
    }
	 	
 // Devide by number of coordinates	 	
    sum_x /= n;	 
    sum_y /= n;	 	
    sum_xy /= n;	 
    sum_x2 /= n;	 	
    sum_y2 /= n;	 		 
    A = -(sum_xy -sum_x*sum_y);	 	
    Bx = sum_x2-sum_x*sum_x;	 
    By = sum_y2-sum_y*sum_y;	 
 		
 // Define best solution, over x or y axis
	 	
    if(fabs(Bx)<fabs(By))
    {
        // Least squire method over y axis	 	
        B = By;	 	
        std::swap(A,B);	 	
    }
    else
    {	 
        // Least squire method over x axis	 	
        B=Bx;	 	
    }	 
	
    C = - ( A*sum_x + B*sum_y);
	
 // Solution of extended least squire method where line if defined as	
 // y = b*x+a	 	
    a = (-C/B);	
    b = (-A/B)