* use transpose() instead of row vectors (more common use case)

* add a word about noalias and performance for BLAS users

1 files changed, 6 insertions, 6 deletions

diff --git a/doc/examples/tut_arithmetic_matrix_mul.cpp b/doc/examples/tut_arithmetic_matrix_mul.cpp
index 63be38241..f21390241 100644
--- a/doc/examples/tut_arithmetic_matrix_mul.cpp
+++ b/doc/examples/tut_arithmetic_matrix_mul.cpp
@@ -7,13 +7,13 @@ int main()
   Matrix2d mat;
   mat << 1, 2,
          3, 4;
-  Vector2d vec(-1,1);
-  RowVector2d rowvec(2,0);
+  Vector2d u(-1,1), v(2,0);
   std::cout << "Here is mat*mat:\n" << mat*mat << std::endl;
-  std::cout << "Here is mat*vec:\n" << mat*vec << std::endl;
-  std::cout << "Here is rowvec*mat:\n" << rowvec*mat << std::endl;
-  std::cout << "Here is rowvec*vec:\n" << rowvec*vec << std::endl;
-  std::cout << "Here is vec*rowvec:\n" << vec*rowvec << std::endl;
+  std::cout << "Here is mat*u:\n" << mat*u << std::endl;
+  std::cout << "Here is u^T*mat:\n" << u.transpose()*mat << std::endl;
+  std::cout << "Here is u^T*v:\n" << u.transpose()*v << std::endl;
+  std::cout << "Here is u*v^T:\n" << u*v.transpose() << std::endl;
   std::cout << "Let's multiply mat by itself" << std::endl;
+  mat = mat*mat;
   std::cout << "Now mat is mat:\n" << mat << std::endl;
 }