code: def idz_snorm(m, n, matveca, matvec, its=20):
      """
      Estimate spectral norm of a complex matrix by the randomized power method.
  
      :param m:
          Matrix row dimension.
      :type m: int
      :param n:
          Matrix column dimension.
      :type n: int
      :param matveca:
          Function to apply the matrix adjoint to a vector, with call signature
          `y = matveca(x)`, where `x` and `y` are the input and output vectors,
          respectively.
      :type matveca: function
      :param matvec:
          Function to apply the matrix to a vector, with call signature
          `y = matvec(x)`, where `x` and `y` are the input and output vectors,
          respectively.
      :type matvec: function
      :param its:
          Number of power method iterations.
      :type its: int
  
      :return:
          Spectral norm estimate.
      :rtype: float
      """
      snorm, v = _id.idz_snorm(m, n, matveca, matvec, its)
      return snorm
  
imports: import scipy.linalg._interpolative
  import numpy
label_desc: Use image node_id 40 for calling a global function with example usage: idz_snorm(m, n, matveca, matvec, its) and returns: snorm