code: def test_spike(self):
      # see 7700
      # Create a curve that is easy to fit at first but gets
      # harder further along.
      # This used to give an outlier bad fit at position 961
      x = np.linspace(0, 10, 1001)
      y = np.cos(x**2 / 5)
      result = lowess(y, x, frac=11 / len(x), it=1)
      assert_(np.all(result[:, 1] > np.min(y) - 0.1))
      assert_(np.all(result[:, 1] < np.max(y) + 0.1))
  
imports: import os
  import numpy
  from numpy.testing import assert_, assert_allclose, assert_almost_equal, assert_equal, assert_raises
  import pytest
  from statsmodels.nonparametric.smoothers_lowess import lowess
  import pandas
label_desc: Use image node_id 15 for calling the TestLowess obj's underlying member method code with example usage: obj.test_spike() without return types