code: def test_tps():
      """Test TPS warping."""
      az = np.linspace(0.0, 2 * np.pi, 20, endpoint=False)
      pol = np.linspace(0, np.pi, 12)[1:-1]
      sph = np.array(np.meshgrid(1, az, pol, indexing="ij"))
      sph.shape = (3, -1)
      assert_equal(sph.shape[1], 200)
      source = _sph_to_cart(sph.T)
      destination = source.copy()
      destination *= 2
      destination[:, 0] += 1
      # fit with 100 points
      warp = SphericalSurfaceWarp()
      assert "no " in repr(warp)
      warp.fit(source[::3], destination[::2])
      assert "oct5" in repr(warp)
      destination_est = warp.transform(source)
      assert_allclose(destination_est, destination, atol=1e-3)
  
imports: import itertools
  import os
  from pathlib import Path
  import numpy
  import pytest
  from numpy.testing import assert_allclose, assert_almost_equal, assert_array_equal, assert_array_less, assert_equal
  import mne
  from mne import read_trans, write_trans
  from mne.datasets import testing
  from mne.fixes import _get_img_fdata
  from mne.io import read_info
  from mne.transforms import _angle_between_quats, _average_quats, _cart_to_sph, _compute_r2, _euler_to_quat, _find_trans, _find_vector_rotation, _fit_matched_points, _get_trans, _MatchedDisplacementFieldInterpolator, _pol_to_cart, _quat_real, _quat_to_affine, _quat_to_euler, _read_fs_xfm, _sph_to_cart, _topo_to_sph, _validate_pipeline, _write_fs_xfm, apply_trans, combine_transforms, get_ras_to_neuromag_trans, invert_transform, quat_to_rot, rot_to_quat, rotation, rotation3d, rotation3d_align_z_axis, rotation_angles, translation
  from mne.transforms import _SphericalSurfaceWarp
label_desc: Use image node_id 1 for calling a global function with example usage: test_tps() without return types