def hamming(u, v):
u = _validate_vector(u)<EOL>v = _validate_vector(v)<EOL>return (u != v).mean()<EOL>
Computes the Hamming distance between two 1-D arrays.

The Hamming distance between 1-D arrays `u` and `v`, is simply the
proportion of disagreeing components in `u` and `v`. If `u` and `v` are
boolean vectors, the Hamming distance is

.. math::

   \\frac{c_{01} + c_{10}}{n}

where :math:`c_{ij}` is the number of occurrences of
:math:`\\mathtt{u[k]} = i` and :math:`\\mathtt{v[k]} = j` for
:math:`k < n`.

Parameters
----------
u : (N,) array_like
    Input array.
v : (N,) array_like
    Input array.

Returns
-------
hamming : double
    The Hamming distance between vectors `u` and `v`.