#include "mtl/matrix.h"#include "mtl/mtl.h"#include "mtl/utils.h"  #include "mtl/linalg_vec.h"/*  Sample OutputArray A:3x3[[1,2,4],[2,4,3],[3,5,6]]Vector y[7,8,9,]Ay[7,46,115,]  */using namespace mtl;typedef matrix< double, triangle<lower>, packed<>, row_major>::type Matrix; typedef dense1D<double> Vector;intmain(){  const int N = 3;    Matrix A(N, N);  Vector y(N), Ay(N);  //C         1              7  //C     A = 2  4       y = 8  //C         3  5  6        9  A(0,0) = 1;  A(1,0) = 2; A(1,1) = 4;  A(2,0) = 3; A(2,1) = 5; A(2,2) = 6;  for (int i=0;i<N;++i)    y[i] = 7+i;    std::cout << "Array A:" << std::endl;  print_all_matrix(A);  std::cout << "Vector y" << std::endl;  print_vector(y);  mult(A, y, Ay);  std::cout << "Ay" << std::endl;  print_vector(Ay);  return 0;}