code: def idd_diffsnorm(m, n, matvect, matvect2, matvec, matvec2, its=20):
      """
      Estimate spectral norm of the difference of two real matrices by the
      randomized power method.
  
      :param m:
          Matrix row dimension.
      :type m: int
      :param n:
          Matrix column dimension.
      :type n: int
      :param matvect:
          Function to apply the transpose of the first matrix to a vector, with
          call signature `y = matvect(x)`, where `x` and `y` are the input and
          output vectors, respectively.
      :type matvect: function
      :param matvect2:
          Function to apply the transpose of the second matrix to a vector, with
          call signature `y = matvect2(x)`, where `x` and `y` are the input and
          output vectors, respectively.
      :type matvect2: function
      :param matvec:
          Function to apply the first 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 matvec2:
          Function to apply the second matrix to a vector, with call signature
          `y = matvec2(x)`, where `x` and `y` are the input and output vectors,
          respectively.
      :type matvec2: function
      :param its:
          Number of power method iterations.
      :type its: int
  
      :return:
          Spectral norm estimate of matrix difference.
      :rtype: float
      """
      return _id.idd_diffsnorm(
          m, n, matvect, matvect2, matvec, matvec2, its
      )
  
imports: import scipy.linalg._interpolative
  import numpy
label_desc: Use image node_id 15 for calling a global function with example usage: idd_diffsnorm(m, n, matvect, matvect2, matvec, matvec2, its) and returns: _id