code: def test_smoothing_limit_1d(self):
      # For large smoothing parameters, the interpolant should approach a
      # least squares fit of a polynomial with the specified degree.
      seq = Halton(1, scramble=False, seed=np.random.RandomState())
  
      degree = 3
      smoothing = 1e8
  
      x = 3 * seq.random(50)
      xitp = 3 * seq.random(50)
  
      y = _1d_test_function(x)
  
      yitp1 = self.build(x, y, degree=degree, smoothing=smoothing)(xitp)
  
      P = _vandermonde(x, degree)
      Pitp = _vandermonde(xitp, degree)
      yitp2 = Pitp.dot(np.linalg.lstsq(P, y, rcond=None)[0])
  
      assert_allclose(yitp1, yitp2, atol=1e-8)
  
imports: import pickle
  import pytest
  import numpy
  from numpy.linalg import LinAlgError
  from numpy.testing import assert_allclose, assert_array_equal
  from scipy.stats.qmc import Halton
  from scipy.spatial import cKDTree
  from scipy.interpolate._rbfinterp import _AVAILABLE, _SCALE_INVARIANT, _NAME_TO_MIN_DEGREE, _monomial_powers, RBFInterpolator
  from scipy.interpolate import _rbfinterp_pythran
label_desc: Use image node_id 2 for calling the TestRBFInterpolatorNeighborsNone obj's underlying member method code with example usage: obj.test_smoothing_limit_1d() without return types