## Copyright (C) 1995, 1996, 1997  Friedrich Leisch
##
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2, or (at your option)
## any later version.
##
## This program is distributed in the hope that it will be useful, but
## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
## General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with this file.  If not, write to the Free Software Foundation,
## 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

## usage:  retval = rectangle_sw (n, b)
##
## Rectangular spectral window. Subfunction used for spectral density
## estimation.

## Author:  FL <Friedrich.Leisch@ci.tuwien.ac.at>
## Description:  Rectangular spectral window

function retval = rectangle_sw (n, b)

  retval = zeros (n, 1);
  retval(1) = 2 / b + 1;

  l = (2:n)' - 1;
  l = 2 * pi * l / n;

  retval(2:n) = sin( (2/b + 1) * l / 2 ) ./ sin (l / 2);

endfunction