code: def test_output_dimensions():
      """Test output dimensions."""
      # test with univariate
      X = _make_nested_from_array(
          np.ones(12), n_instances=10, n_columns=1
      )
  
      p = PAA(num_intervals=5).fit(X)
      res = p.transform(X)
  
      # get the dimension of the generated dataframe.
      corr_time_series_length = res.iloc[0, 0].shape[0]
      num_rows = res.shape[0]
      num_cols = res.shape[1]
  
      assert corr_time_series_length == 5
      assert num_rows == 10
      assert num_cols == 1
  
      # test with multivariate
      X = _make_nested_from_array(
          np.ones(12), n_instances=10, n_columns=5
      )
  
      p = PAA(num_intervals=5).fit(X)
      res = p.transform(X)
  
      # get the dimension of the generated dataframe.
      corr_time_series_length = res.iloc[0, 0].shape[0]
      num_rows = res.shape[0]
      num_cols = res.shape[1]
  
      assert corr_time_series_length == 5
      assert num_rows == 10
      assert num_cols == 5
  
file_path: sktime/sktime/transformations/panel/dictionary_based/tests/test_paa.py
imports: import numpy
  import pandas
  import pytest
  from sktime.transformations.panel.dictionary_based._paa import PAA
  from sktime.utils._testing.panel import _make_nested_from_array
label_desc: Use image node_id 3 for calling a global function with example usage: test_output_dimensions() without return types