flattopwin

% flattopwin(n, [periodic|symmetric])
%
% Return the window f(w):
%
%   f(w) = 1 - 1.93 cos(2 pi w) + 1.29 cos(4 pi w)
%            - 0.388 cos(6 pi w) + 0.0322cos(8 pi w)
%
% where w = i/(n-1) for i=0:n-1 for a symmetric window, or
% w = i/n for i=0:n-1 for a periodic window.  The default
% is symmetric.  The returned window is normalized to a peak
% of 1 at w = 0.5.
%
% This window has low pass-band ripple, but high bandwidth.
%
% According to [1]:
%
%    The main use for the Flat Top window is for calibration, due
%    to its negligible amplitude errors.
%
% [1] Gade, S; Herlufsen, H; (1987) 'Use of weighting functions in DFT/FFT
% analysis (Part I)', Bruel & Kjaer Technical Review No.3.