TSP (libtsp) - FIfWinRCos

FIfWinRCos

Routine

void FIfWinRCos (float win[], int N, int Nadv)

Purpose

Generate a raised-cosine window

Description

This routine generates a raised-cosine window that can be used for processing overlapped frames of data. The window has sinusoidal transitions at each end. The middle portion is flat. The values returned do not include the end-points, i.e. all of the values returned are non-zero. The example below shows a raised-cosine window with N=9 and Nadv=7. Only the points marked with x's are returned.

              x x x x x
            x           x
          x               x
  o-o-o-o-------------------o-o-o-o
          0 1 2 3 4 5 6 7 8

The parameter Nadv is the number of points by which the window must be advanced for the transition regions of two adjacent windows to add up to unity. The total window length is N+2, but the two end points which are zero are not returned. The parameters must satisfy

  Nadv-1 <= N <= 2*Nadv-1 .

The lefthand equality gives a rectangular window (the window coefficients are all equal to one); the righthand equality gives a full raised-cosine window. For values between these extremes, the window has a constant portion with 2*Nadv-N points.

Parameters

<- float win[]: Array containing the window values
-> int N: Number of window values
-> int Nadv: Window advance

Author / revision