code: def test_init():
      """
      Test that we can initialize the MatrixGroup subclasses
      """
      O_A = MG.O(A, "xy")
      GLR_A = MG.GLR(A, "xy")
      GLZ_A = MG.GLZ(A, "xy")
      SO_A = MG.SO(np.identity(2), "xy")
  
      B = np.array(
          [[np.sin(0.75), np.cos(0.75)], [-np.cos(0.75), np.sin(0.75)]]
      )
      O_B = MG.O(B, "xy")
      SO_B = MG.O(B, "xy")
  
      B[1] = -B[1]
      pytest.raises(ValueError, MG.SO, B, "xy")
      O_B = MG.O(B, "xy")
  
file_path: nipy/nipy/core/reference/tests/test_matrix_groups.py
imports: import numpy
  import pytest
  from scipy.linalg import expm
  import nipy.core.reference.tests.matrix_groups
  from nipy.core.api import ArrayCoordMap
label_desc: Use image node_id 1 for calling a global function with example usage: test_init() without return types