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## -*- texinfo -*-
## @deftypefn {} {@var{c} =} rectangle_sw (@var{n}, @var{b})
## Rectangular spectral window.
##
## Subfunction used for spectral density estimation.
## @seealso{spectral_xdf}
## @end deftypefn

function c = rectangle_sw (n, b)

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

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

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

endfunction