comp_window.m

Matlab时频分析工具箱,希望能对大家有所帮助啊

function [g,info] = comp_window(g,a,M,L,wilson,callfun);
%COMP_WINDOW  Compute the window from text or cell array.
%   Usage: [g,info] = comp_window(g,a,M,L,wilson,callfun);
%
%   [g,info]=COMP_WINDOW(g,a,M,L,wilson,callfun) will compute the window
%   from a text description or a cell array containing additional
%   parameters.
%
%   The structure info provides some information about the computed
%   window:
%
%      info.gauss   - True if the window is a Gaussian.
%
%      info.tfr     - Time/frequency support ratio of the window. Set
%                     whenever it makes sense.
% 

% 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 3 of the License, 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 program.  If not, see <http://www.gnu.org/licenses/>.
  
% Default values.
info.gauss=0;
    
% Create window if string was given as input.
if ischar(g)
  switch(lower(g))
   case {'pgauss','gauss'}
    g=comp_pgauss(L,a*M/L,0);
    info.gauss=1;
    info.tfr=a*M/L;
   case {'dualgauss','gaussdual'}
    g=comp_pgauss(L,a*M/L,0);
    g=candual(g,a,M);
    if wilson
      g=2*g;
    end;
    info.tfr=a*M/L;
   case {'tight'}
    g=cantight(a,M,L);
    if wilson
      g=g*sqrt(2);
    end;
    info.tfr=a*M/L;
   case {'sqrthann','sqrthan'}
    g=firwin('sqrthann',M);
   otherwise
    error('Unknown window type.');
  end;
end;

if iscell(g)
  if isempty(g) || ~ischar(g{1})
    error('First element of window cell array must be a character string.');
  end;
  
  switch(lower(g{1}))
   case {'pgauss','gauss'}
    [g,info.tfr]=pgauss(L,g{2:end});
    info.gauss=1;
   case {'psech','sech'}
    g=psech(L,g{2:end});
   otherwise
    error('Only Gaussian windows can be passed as cell arrays.');
  end;
end;