title: How to find all neighbors of a given point in a delaunay triangulation using scipy.spatial.Delaunay?
body: <p>I have been searching for an answer to this question but cannot find anything useful.</p>
  
  <p>I am working with the python scientific computing stack (scipy,numpy,matplotlib) and I have a set of 2 dimensional points, for which I compute the Delaunay traingulation (<a href="https://en.wikipedia.org/wiki/Delaunay_triangulation" rel="noreferrer">wiki</a>) using <code>scipy.spatial.Delaunay</code>.</p>
  
  <p>I need to write a function that, given any point <code>a</code>, will return all other points which are vertices of any simplex (i.e. triangle) that <code>a</code> is also a vertex of (the neighbors of <code>a</code> in the triangulation). However, the documentation for <code>scipy.spatial.Delaunay</code> (<a href="http://docs.scipy.org/doc/scipy/reference/generated/scipy.spatial.Delaunay.html" rel="noreferrer">here</a>) is pretty bad, and I can't for the life of me understand how the simplices are being specified or I would go about doing this. Even just an explanation of how the <code>neighbors</code>, <code>vertices</code> and <code>vertex_to_simplex</code> arrays in the Delaunay output are organized would be enough to get me going.</p>
  
  <p>Much thanks for any help.</p>