spectral_adf Return the spectral density estimator given a vector of autocovariances C, window name WIN, and bandwidth, B. spectral_adf(C) spectral_adf(C, WIN) spectral_adf(C, WIN, B) C: Autocovariances WIN: Window names B: Bandwidth Return the spectral density estimator given a vector ofautocovariances C, window name WIN, and bandwidth, B. The window name, e.g., "triangle" or "rectangle" is used to search for a function called 'WIN_lw'. If WIN is omitted, the triangle window is used. If B is omitted, '1 / sqrt (length (C))' is used.