## Mercurial > hg > octave-max

### view scripts/signal/spectral_adf.m @ 15489:481417a57a2d

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improve sign and signbit docs
* mappers.cc (Fsign): Note sign (-0) is 0. Add @seealso for signbit.
(Fsignbit): Add @seealso for sign.

author | John W. Eaton <jwe@octave.org> |
---|---|

date | Thu, 04 Oct 2012 10:20:59 -0400 |

parents | 72c96de7a403 |

children |

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## Copyright (C) 1995-2012 Friedrich Leisch ## ## This file is part of Octave. ## ## Octave 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 3 of the License, or (at ## your option) any later version. ## ## Octave 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 Octave; see the file COPYING. If not, see ## <http://www.gnu.org/licenses/>. ## -*- texinfo -*- ## @deftypefn {Function File} {} spectral_adf (@var{c}, @var{win}, @var{b}) ## Return the spectral density estimator given a vector of ## autocovariances @var{c}, window name @var{win}, and bandwidth, ## @var{b}. ## ## The window name, e.g., @code{"triangle"} or @code{"rectangle"} is ## used to search for a function called @code{@var{win}_sw}. ## ## If @var{win} is omitted, the triangle window is used. If @var{b} is ## omitted, @code{1 / sqrt (length (@var{x}))} is used. ## @end deftypefn ## Author: FL <Friedrich.Leisch@ci.tuwien.ac.at> ## Description: Spectral density estimation function retval = spectral_adf (c, win, b) cr = length (c); if (columns (c) > 1) c = c'; endif if (nargin < 3) b = 1 / ceil (sqrt (cr)); endif if (nargin == 1) w = triangle_lw (cr, b); else win = str2func (cstrcat (win, "_lw")); w = feval (win, cr, b); endif c = c .* w; retval = 2 * real (fft (c)) - c(1); retval = [(zeros (cr, 1)), retval]; retval(:, 1) = (0 : cr-1)' / cr; endfunction