title: What is the MathNet equivalent of numpy array[0,:] *= 1.23
body: <p>I have to port some python (numpy) code in c# (MathNet).
  I can write in python:</p>
  
  <pre><code>mtx = np.array([[0,1,2],[3,4,5]])
  mtx[0,:] *= 1.23    #multiply all elements in row 0 by 1.23
  </code></pre>
  
  <p>How can I do this in MathNet? Is there better (faster) solution than:</p>
  
  <pre class="lang-cs prettyprint-override"><code> Matrix&lt;double&gt; mtx = Matrix&lt;double&gt;.Build.Dense(2,3);
   //...
   for(int i = 0; i &lt; mtx.ColumnCount; i++)
      mtx[0,i] *= 1.23;
  </code></pre>
  
  <p>?</p>