title: Error when trying to interpolate using SmoothSphereBivariateSpline(): "ValueError: Error code returned by bispev: 10"
body: <p>I want to interpolate data, which is randomly scattered on the surface of a sphere, onto a regular longitude/latitude grid. I tried to do this with <code>SmoothSphereBivariateSpline()</code> from the <code>scipy.interpolate</code> package (see the code below). </p>
  
  <pre><code>import numpy as np
  from scipy.interpolate import SmoothSphereBivariateSpline
  
  #Define the input data and the original sampling points
  NSamp = 2000
  Theta = np.random.uniform(0,np.pi,NSamp)
  Phi   = np.random.uniform(0,2*np.pi, NSamp)
  Data  = np.ones(NSamp)
  
  Interpolator = SmoothSphereBivariateSpline(Theta, Phi, Data, s=3.5)
  
  #Prepare the grid to which the input shall be interpolated
  NLon = 64
  NLat = 32
  GridPosLons = np.arange(NLon)/NLon * 2 * np.pi
  GridPosLats = np.arange(NLat)/NLat * np.pi
  LatsGrid, LonsGrid = np.meshgrid(GridPosLats, GridPosLons)
  Lats = LatsGrid.ravel()
  Lons = LonsGrid.ravel()
  
  #Interpolate
  Interpolator(Lats, Lons)
  </code></pre>
  
  <p>However, when I execute this code it gives me the following error:</p>
  
  <pre><code>ValueError: Error code returned by bispev: 10
  </code></pre>
  
  <p>Does anyone know what the problem is and how to fix it? Is this a bug or am I doing something wrong?</p>