title: Set node direction on graphviz
body: <p>Suppose this code using neato:</p>
  
  <pre><code>graph sample {
    layout=neato
    overlap=false
    splines=true
    tailclip=false
    headclip=false
    A -- I
    A -- J
    A -- B
    A -- H
    A -- E
    A -- K
    B -- D
    B -- C
    B -- L
    C -- M
    C -- N
    C -- O
    D -- P
    D -- Q
    E -- R
    F -- A
    G -- F
    H -- J
  }
  </code></pre>
  
  <p>This gives us this diagram:</p>
  
  <p><img src="https://i.stack.imgur.com/RPX2a.png" alt="neato diagram"></p>
  
  <p>What I need is to place a node <code>X</code>, always fixed in a position south from his parent node. i.e. If I put another relation <code>A -- X</code>, <code>X</code> should be always placed south from <code>A</code>. And I don't really care where everything else ends up.</p>
  
  <p>I've looked into the <code>pos</code> attribute, but it doesn't seems to be the solution since <code>X</code> is not really in a fixed position, but on a position relative to his relation.</p>
  
  <p>Also <code>tailport</code> and <code>headport</code>, but they only define from where the edge will come out/in, but don't really affect the direction of the node.</p>
  
  <p><strong>Update</strong></p>
  
  <p>An additional image to make things clearer:</p>
  
  <p><img src="https://i.stack.imgur.com/KtECi.jpg" alt="x should be south from his parent"></p>
  
  <p>I don't require neato, but I don't want the graph to look like a UD or LR dot tree, I don't want it to be linearly ordered. circo, fdp, sfdp, twopi are alright too.</p>