title: Perform LU decomposition without pivoting in MATLAB
body: <p>How can I implement the function <code>lu(A)</code> in MATLAB so that <code>L*U</code> is directly <code>A</code> and I also get the real <code>L</code> matrix?</p>
  
  <p>When I use <code>[L,U] = lu(A)</code>, MATLAB doesn't give me the right <code>L</code> matrix.  When I use <code>[L,U,P]</code> = lu(A), I need to implement <code>P*A = L*U</code>, but I only want to multiply <code>L*U</code> to receive A.</p>