code: def test_mam_distances():
      xyz1 = np.array([[0, 0, 0], [1, 0, 0], [2, 0, 0], [3, 0, 0]])
      xyz2 = np.array([[0, 1, 1], [1, 0, 1], [2, 3, -2]])
      # dm=array([[ 2,  2, 17], [ 3,  1, 14], [6,  2, 13], [11,  5, 14]])
      # this is the distance matrix between points of xyz1
      # and points of xyz2
      xyz1 = xyz1.astype("float32")
      xyz2 = xyz2.astype("float32")
      zd2 = pf.mam_distances(xyz1, xyz2)
      assert_almost_equal(zd2[0], 1.76135602742)
  
file_path: dipy/dipy/tracking/tests/test_distances.py
imports: import warnings
  import numpy
  from numpy.testing import assert_array_almost_equal, assert_equal, assert_almost_equal, assert_array_equal
  from dipy.testing import assert_true
  from dipy.testing.decorators import set_random_number_generator
  from dipy.tracking import distances
  from dipy.tracking.streamline import set_number_of_points
  from dipy.data import get_fnames
  from dipy.io.streamline import load_tractogram
label_desc: Use image node_id 4 for calling a global function with example usage: test_mam_distances() without return types