class_docstr: CMVN unittest Class
docstr: test compute cmvn 
docstr_tok: ["test","compute","cmvn"]
code: def testComputeCmvn(self):  # pylint: disable=invalid-name
      """test compute cmvn"""
      np.random.seed(12)
      feat_size = 40
      delta_deltas = True
      shape = [2, 10, feat_size, 3 if delta_deltas else 1]
  
      sums, square, count = utils.create_cmvn_statis(
          feat_size, delta_deltas
      )
  
      feat = np.random.randn(*shape)
      feat = feat.astype(np.float32)
      sums, square, count = utils.update_cmvn_statis(
          feat, sums, square, count
      )
      mean, var = utils.compute_cmvn(sums, square, count)
      mean_true, var_true = np.mean(feat, axis=(0, 1)), np.var(
          feat, axis=(0, 1)
      )
  
      self.assertAllEqual(mean.shape, [1] + shape[2:])
      self.assertAllClose(np.squeeze(mean, axis=0), mean_true)
      self.assertAllClose(np.squeeze(var, axis=0), var_true)
  
file_path: delta/delta/utils/cmvn_test.py
imports: import os
  import numpy
  import delta.compat
  from delta import utils
label_desc: Use image node_id 5 for calling the CmvnTest obj's underlying member method code with example usage: obj.testComputeCmvn() without return types