code: def test_solve_2d_symmetric_positive_definite():
      # Select some arbitrary right-hand sides
      bs = [
          np.array([1.1, 2.2]),
          np.array([1e-2, 3e-3]),
          np.array([1e2, 1e3]),
          np.array([1e-5, 1e5]),
      ]
  
      # Select arbitrary symmetric positive-definite matrices
      As = []
  
      # Identity
      identity = np.array([1.0, 0.0, 1.0])
      As.append(identity)
  
      # Small determinant
      small_det = np.array([1e-3, 1e-4, 1e-3])
      As.append(small_det)
  
      # Large determinant
      large_det = np.array([1e6, 1e4, 1e6])
      As.append(large_det)
  
      for A in As:
          AA = np.array([[A[0], A[1]], [A[1], A[2]]])
          det = np.linalg.det(AA)
          for b in bs:
              expected = np.linalg.solve(AA, b)
              actual = ssd.solve_2d_symmetric_positive_definite(
                  A, b, det
              )
              assert_allclose(expected, actual, rtol=1e-9, atol=1e-9)
  
file_path: dipy/dipy/align/tests/test_sumsqdiff.py
imports: import numpy
  from dipy.align import floating
  from dipy.align import sumsqdiff
  from numpy.testing import assert_equal, assert_almost_equal, assert_array_almost_equal, assert_allclose
  from dipy.testing.decorators import set_random_number_generator
label_desc: Use image node_id 5 for calling a global function with example usage: test_solve_2d_symmetric_positive_definite() without return types