title: Alternatives to scipy.interpolate.griddata that don't hang on aligned points
body: <p>I have a point dataset that I'm trying to interpolate on a grid.  These points are aligned in grid fashion with some points missing see below: <img src="https://i.stack.imgur.com/mtXwY.png" alt="enter image description here"></p>
  
  <p>To complicate it, it's possible that other input pointsets may not align on a grid, so I'm trying to use <code>scipy.interpolate.griddata</code> to interpolate these values onto a regular grid.  However, sometimes my underlying grid aligns perfectly with the sampling rate of the input point dataset and <code>griddata</code> hangs.  According to <a href="https://stackoverflow.com/a/5623980/42897">this question</a> <code>scipy.interpolate.griddata</code> operates poorly if the sample occurs across 3 points that are perfectly aligned which sometimes happens for me.</p>
  
  <p>Is there a high performance alternative for interpolation of point data onto a regular grid in Python?</p>