Returns the input series, windowed by a polynomial similar to a Hanning window. To window an arbitrary section of the series, subtract or add an offset to it to adjust the centre of the window; for an offset of k, the call would be cubicwgt (s - k). Similarly, the radius of the window is 1; if an arbitrary radius r is desired, dividing the series by the radius after centering is the best way to adjust to fit the window: cubicwgt ((s - k) / r).
The windowing function itself is: w = 1 + ( x ^ 2 * ( 2 x - 3 ) ), x in [-1,1], else w = 0.
Package: lssa