def _split_arrays(arrays, extra_args, nparts):
    """
    Split the coordinate arrays into nparts. Add extra_args to each part.

    Example::

    >>> chunks = _split_arrays([[1, 2, 3, 4, 5, 6]], ['meh'], 3)
    >>> chunks[0]
    [[1, 2], 'meh']
    >>> chunks[1]
    [[3, 4], 'meh']
    >>> chunks[2]
    [[5, 6], 'meh']

    """
    size = len(arrays[0])
    n = size//nparts
    strides = [(i*n, (i + 1)*n) for i in range(nparts - 1)]
    strides.append((strides[-1][-1], size))
    chunks = [[x[low:high] for x in arrays] + extra_args
              for low, high in strides]
    return chunks