code: def as2d(ar):
      """
      If the input array is 2D return it, if it is 1D, append a dimension,
      making it a column vector.
      """
      if ar.ndim == 2:
          return ar
      else:  # Assume 1!
          aux = np.array(ar, copy=False)
          aux.shape = (ar.shape[0], 1)
          return aux
  
file_path: catboost/contrib/python/scipy/py2/scipy/sparse/linalg/eigen/lobpcg/lobpcg.py
imports: from __future__ import division, print_function, absolute_import
  import numpy
  from numpy.testing import assert_allclose
  from scipy._lib.six import xrange
  from scipy.linalg import inv, eigh, cho_factor, cho_solve, cholesky
  from scipy.sparse.linalg import aslinearoperator, LinearOperator
  from scipy.sparse.sputils import bmat
label_desc: Use image node_id 3 for calling a global function with example usage: as2d(ar) and returns: ar, aux