w = bohmanwin(L)
w = bohmanwin(L) returns
L-point Bohman window in column vector
A Bohman window is the convolution of two half-duration cosine lobes.
In the time domain, it is the product of a triangular window and a
single cycle of a cosine with a term added to set the first derivative
to zero at the boundary. Bohman windows fall off as 1/w4.
 Harris, Fredric J. "On the Use of Windows for Harmonic Analysis with the Discrete Fourier Transform." Proceedings of the IEEE®. Vol. 66, January 1978, pp. 51–83.