code: def precalculate_VtinvSigmaV(V, invSigma):
      tril_ind = np.tril_indices(V.shape[0])
      VtinvSigmaV = np.empty((V.shape[1], len(tril_ind[0])), V.dtype)
      for c in range(V.shape[1]):
          VtinvSigmaV[c, :] = np.dot(
              V[:, c, :] * invSigma[np.newaxis, c, :], V[:, c, :].T
          )[tril_ind]
      return VtinvSigmaV
  
file_path: espnet/egs/libri_css/asr1/diarization/VB_diarization.py
imports: import numexpr
  import numpy
  import scipy.linalg
  from scipy.sparse import coo_matrix
label_desc: Use image node_id 2 for calling a global function with example usage: precalculate_VtinvSigmaV(V, invSigma) and returns: VtinvSigmaV