//// Copyright 1997, University of Notre Dame.// Authors: Andrew Lumsdaine, Jeremy G. Siek//// This file is part of the Matrix Template Library//// You should have received a copy of the License Agreement for the// Matrix Template Library along with the software;  see the// file LICENSE.  If not, contact Office of Research, University of Notre// Dame, Notre Dame, IN  46556.//// Permission to modify the code and to distribute modified code is// granted, provided the text of this NOTICE is retained, a notice that// the code was modified is included with the above COPYRIGHT NOTICE and// with the COPYRIGHT NOTICE in the LICENSE file, and that the LICENSE// file is distributed with the modified code.//// LICENSOR MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.// By way of example, but not limitation, Licensor MAKES NO// REPRESENTATIONS OR WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY// PARTICULAR PURPOSE OR THAT THE USE OF THE LICENSED SOFTWARE COMPONENTS// OR DOCUMENTATION WILL NOT INFRINGE ANY PATENTS, COPYRIGHTS, TRADEMARKS// OR OTHER RIGHTS.//// $Id: general_matvec_mult.cc,v 1.2 2000/08/28 15:22:59 jsiek Exp $//#include "mtl/matrix.h"#include "mtl/mtl.h"#include "mtl/utils.h"  #include "mtl/linalg_vec.h"#include <math.h>/*  Rotates the vector.  Sample Output  Original vector: [3,4,]  Rotated vector:  [-2,1.5,]    */using namespace mtl;intmain(){  //begin  typedef matrix< double,                   rectangle<2,2>,                   dense<external>,                   column_major>::type Matrix;   typedef dense1D<double> Vector;  double pi, theta;  double dA[4];  Matrix rot(dA);  Vector vec1(Matrix::N),vec2(Matrix::N);  pi = 4.0 * atan (1.0);  theta = pi / 2.0;  rot(0,0) = cos(theta);  rot(1,0) = sin(theta);  rot(0,1) = -sin(theta);  rot(1,1) = cos(theta);  vec1[0] = 3.0;  vec1[1] = 4.0;  //end  std::cout << std::endl;  std::cout << "Original vector: ";  print_vector(vec1);  std::cout << std::endl;  //begin  mult(rot, scaled(vec1, 0.5), vec2);  //end  std::cout << "Rotated vector: ";  print_vector(vec2);  return 0;}