text: import math
  
  try:
      from ulab import scipy, numpy as np
  except ImportError:
      import scipy
      import numpy as np
  
  ## test cholesky solve
  L = np.array([[3, 0, 0, 0], [2, 1, 0, 0], [1, 0, 1, 0], [1, 2, 1, 8]])
  b = np.array([4, 2, 4, 2])
  
  # L needs to be a lower triangular matrix
  result = scipy.linalg.cho_solve(L, b)
  ref_result = np.array([-0.01388888888888906, -0.6458333333333331, 2.677083333333333, -0.01041666666666667])
  
  for i in range(4):
          print(math.isclose(result[i], ref_result[i], rel_tol=1E-6, abs_tol=1E-6))
  
  ## test cholesky and cho_solve together
  C = np.array([[18, 22,  54,  42], [22, 70,  86,  62], [54, 86, 174, 134], [42, 62, 134, 106]])
  L = np.linalg.cholesky(C)
  
  # L is a lower triangular matrix obtained by performing cholesky of positive-definite linear system
  result = scipy.linalg.cho_solve(L, b)
  ref_result = np.array([6.5625, 1.1875, -2.9375, 0.4375])
  
  for i in range(4):
          print(math.isclose(result[i], ref_result[i], rel_tol=1E-6, abs_tol=1E-6))
  