title: TypeError when calling scipy griddata
body: <p>I'm having an issue with scipy.interpolate's griddata function. I developed a quick interpolator using griddata in a sandbox, then once I had the interpolator how I liked it, a copied the function into a larger model I had developed. Here is the function:</p>
  
  <pre><code>def windGrid(*sensors):
      """Creates grids of wind speed components"""
      xb = [0, 0, num_x, num_x]
      yb = [0, num_y, num_y, 0]
  
      xs = [s.lng for s in sensors]
      ys = [s.lat for s in sensors]
      us = [s.u for s in sensors]
      vs = [s.v for s in sensors]
  
      ub, vb = boundaryWeighting(*sensors)
  
      x = xb+xs
      y = yb+ys
      u = ub+us
      v = vb+vs
  
      x_grid, y_grid = np.mgrid[0:num_x, 0:num_y]
  
      zx = griddata((x, y), u, (x_grid, y_grid))
      zy = griddata((x, y), v, (x_grid, y_grid))
  
     return zx, zy
  </code></pre>
  
  <p>The boundaryWeighting() function simply returns wind speed components of the corners of the grid so that interpolations can be made within. Now here is the strange part... When I call griddata in the sandbox (i.e. without other independent functions around it), it works fine. However, when called in the python file to which it was copied, it returns this error:</p>
  
  <pre><code>TypeError: griddata() takes at least 5 arguments (3 given)
  </code></pre>
  
  <p>According to the Scipy documentation, griddata takes 5 arguments, but the last two are optional. I tried inserting the optional arguments (i.e. method and fill_val), but then I got this error:</p>
  
  <pre><code>TypeError: griddata() got an unexpected keyword argument 'method'
  </code></pre>
  
  <p>So it seems that the python interpreter is referencing a different version/function of griddata in the different python files.</p>
  
  <p>Here is why this doesn't make sense:
  1. Both files are in the same directory, and are using the same interpreter
  2. Both files reference the same Scipy version, 0.12.0</p>
  
  <p>I've checked all my variable/function assignments and there are no overlaps. Any clues as to why this would be happening?</p>
  
  <p>Thanks</p>