title: Drawing a surface with x,y,z points
body: <p>I have a list of <code>x</code>, <code>y</code>, <code>z</code> in this form:</p>
  
  <pre><code>   -0.2894    1.2835    0.5405
     -0.8171   -0.3034    0.1824
      2.7864    0.5506    0.0037
  </code></pre>
  
  <p>I could plot using <code>plot3(x,y,z, '*')</code> and it works fine.</p>
  
  <p>Now I would like to draw a surface, but when I do:</p>
  
  <pre><code>&gt;&gt; surf(x,y,z)
  ??? Error using ==&gt; surf at 78
  Z must be a matrix, not a scalar or vector.
  </code></pre>
  
  <p>How should I draw it?</p>