code: def test_output_of_transformer():
      """Test that the transformer has changed the data correctly."""
      X = _make_nested_from_array(
          np.array([4, 6, 10, 12, 8, 6, 5, 5]),
          n_instances=1,
          n_columns=1,
      )
  
      s = SlopeTransformer(num_intervals=2).fit(X)
      res = s.transform(X)
      orig = convert_list_to_dataframe(
          [[(5 + math.sqrt(41)) / 4, (1 + math.sqrt(101)) / -10]]
      )
      orig.columns = X.columns
      assert check_if_dataframes_are_equal(res, orig)
  
      X = _make_nested_from_array(
          np.array([-5, 2.5, 1, 3, 10, -1.5, 6, 12, -3, 0.2]),
          n_instances=1,
          n_columns=1,
      )
      s = s.fit(X)
      res = s.transform(X)
      orig = convert_list_to_dataframe(
          [
              [
                  (104.8 + math.sqrt(14704.04)) / 61,
                  (143.752 + math.sqrt(20790.0775)) / -11.2,
              ]
          ]
      )
      orig.columns = X.columns
      assert check_if_dataframes_are_equal(res, orig)
  
file_path: sktime/sktime/transformations/panel/tests/test_slope_transformer.py
imports: import math
  import numpy
  import pandas
  import pytest
  from sktime.transformations.panel.slope import SlopeTransformer
  from sktime.utils._testing.panel import _make_nested_from_array
label_desc: Use image node_id 2 for calling a global function with example usage: test_output_of_transformer() without return types