code: def isspmatrix_dia(x):
      """Is `x` of dia_matrix type?
  
      Parameters
      ----------
      x
          object to check for being a dia matrix
  
      Returns
      -------
      bool
          True if `x` is a dia matrix, False otherwise
  
      Examples
      --------
      >>> from scipy.sparse import dia_array, dia_matrix, coo_matrix, isspmatrix_dia
      >>> isspmatrix_dia(dia_matrix([[5]]))
      True
      >>> isspmatrix_dia(dia_array([[5]]))
      False
      >>> isspmatrix_dia(coo_matrix([[5]]))
      False
      """
      return isinstance(x, dia_matrix)
  
imports: import numpy
  from ._matrix import spmatrix
  from ._base import issparse, _formats, _spbase, sparray
  from ._data import _data_matrix
  from ._sputils import isshape, upcast_char, getdtype, get_sum_dtype, validateaxis, check_shape
  from ._sparsetools import dia_matvec
label_desc: Use image node_id 1 for calling a global function with example usage: isspmatrix_dia(x) and returns: isinstance