title: Scipy Interpolate RectBivariateSpline constructor returns an error
body: <p>I am trying to instantiate a Scipy Interpolate RectBivariateSpline as follows:</p>
  
  <pre><code>import numpy as np
  from scipy.interpolate import RectBivariateSpline
  
  x = np.array([1,2,3,4])
  y = np.array([1,2,3])
  vals = np.array([
      [4,1,4],
      [4,2,3],
      [3,7,4],
      [2,4,5]
  ])
  
  print(x.shape)  # (4,)
  print(y.shape)  # (3,)
  print(vals.shape)  # (4, 3)
  
  rect_B_spline = RectBivariateSpline(x, y, vals)
  </code></pre>
  
  <p>However, it returns this error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "path/file", line 15, in &lt;module&gt;
      rect_B_spline = RectBivariateSpline(x, y, vals)
    File "path/file", line 1061, in __init__
      ye, kx, ky, s)
  dfitpack.error: (my&gt;ky) failed for hidden my: regrid_smth:my=3
  </code></pre>
  
  <p>Would appreciate any clues as to what the dfitpack error describes and how to resolve.</p>