title: Multiplication of each matrix column by each vector element using Eigen C++ Library
body: <p>I need to multiply each matrix column by each vector element using <a href="http://eigen.tuxfamily.org" rel="noreferrer">Eigen C++ library</a>. I tried colwise without success.</p>
  
  <p>Sample data:</p>
  
  <pre><code>Eigen::Matrix3Xf A(3,2); //3x2
  A &lt;&lt; 1 2,
       2 2,
       3 5;
  
  Eigen::Vector3f V = Eigen::Vector3f(2, 3);
  
  //Expected result
  C = A.colwise()*V;
  
  //C
  //2 6,
  //4 6,
  //6 15
  //this means C 1st col by V first element and C 2nd col by V 2nd element.
  </code></pre>
  
  <p>Matrix A can have 3xN and V Nx1. Meaning (cols x rowls).</p>