code: def power_iteration_kron(
      A, C, max_iter=1000, tol=1e-3, random_state=0
  ):
      """Find the largest singular value for the matrix kron(C.T, A).
  
      It uses power iterations.
  
      Parameters
      ----------
      A : array
          An array
      C : array
          An array
      max_iter : int
          Maximum number of iterations
      %(random_state)s
  
      Returns
      -------
      L : float
          largest singular value
  
      Notes
      -----
      http://en.wikipedia.org/wiki/Power_iteration
      """
      AS_size = C.shape[0]
      rng = check_random_state(random_state)
      B = rng.randn(AS_size, AS_size)
      B /= np.linalg.norm(B, "fro")
      ATA = np.dot(A.T, A)
      CCT = np.dot(C, C.T)
      L0 = np.inf
      for _ in range(max_iter):
          Y = np.dot(np.dot(ATA, B), CCT)
          L = np.linalg.norm(Y, "fro")
  
          if abs(L - L0) < tol:
              break
  
          B = Y / L
          L0 = L
      return L
  
imports: from math import sqrt
  import numpy
  from ..utils import check_random_state, fill_doc, logger, verbose
label_desc: Use image node_id 1 for calling a global function with example usage: power_iteration_kron(A, C, max_iter, tol, random_state) and returns: L