def window_bartlett(N):
from numpy import bartlett<EOL>return bartlett(N)<EOL>
r"""Bartlett window (wrapping of numpy.bartlett) also known as Fejer

    :param int N: window length

    The Bartlett window is defined as

    .. math:: w(n) = \frac{2}{N-1} \left(
              \frac{N-1}{2} - \left|n - \frac{N-1}{2}\right|
              \right)

    .. plot::
        :width: 80%
        :include-source:

        from spectrum import window_visu
        window_visu(64, 'bartlett')

    .. seealso:: numpy.bartlett, :func:`create_window`, :class:`Window`.