Parzen (de la Vallée-Poussin) window
w = parzenwin(L)
w = parzenwin(L) returns the L-point Parzen (de la Vallée-Poussin) window in a column vector, w. Parzen windows are piecewise-cubic approximations of Gaussian windows. Parzen window sidelobes fall off as 1/ω4. See Definitions for the equation that defines the Parzen window.
 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.