code: def _validate_vector(u, dtype=None):
      # XXX Is order='c' really necessary?
      u = np.asarray(u, dtype=dtype, order="c").squeeze()
      # Ensure values such as u=1 and u=[1] still return 1-D arrays.
      u = np.atleast_1d(u)
      if u.ndim > 1:
          raise ValueError("Input vector should be 1-D.")
      return u
  
imports: from __future__ import division, print_function, absolute_import
  import warnings
  import numpy
  from functools import partial
  from collections import namedtuple
  from scipy._lib.six import callable, string_types
  from scipy._lib.six import xrange
  from scipy._lib._util import _asarray_validated
  from .None import _distance_wrap
  from .None import _hausdorff
  from ..linalg import norm
  from ..special import rel_entr
label_desc: Use image node_id 14 for calling a global function with example usage: _validate_vector(u, dtype) and returns: u