title: How to set bounds for kriging results
body: <p>I am using OrdinaryKriging for surface interpolation, I wrote the following lines of code:</p>
  <pre><code>import pykrige
  
  from pykrige.ok import OrdinaryKriging
  
  #krigging with pykrige
  OK = OrdinaryKriging(
      X, 
      Y, 
      E, 
      variogram_model='gaussian',
      verbose=True,
      enable_plotting=True)
  
  gridx = np.arange(0, 1000, 1, dtype='float64')
  gridy = np.arange(0, 1000, 1, dtype='float64')
  zstar, ss = OK.execute(&quot;grid&quot;, gridx, gridy)
  cax = plt.imshow(zstar, extent=(0, 1000, 0, 1000), origin='upper')
  plt.scatter(X, Y, c='k', marker='x')
  cbar=plt.colorbar(cax)
  plt.title('Illuminance distribution')
  </code></pre>
  <p>X and Y define the location and E is illuminance, the quantity I want to interpolate with the algorithm from a list of known ones.</p>
  <p>I get the following plot as the output:
  <a href="https://i.stack.imgur.com/Vgo34.png" rel="nofollow noreferrer">enter image description here</a></p>
  <p>The values Im looking for must logically be greater than or equal to zero, but I am getting negative. Is there any way to define that for the algorithm?</p>