spreadfun.m

来自「Matlab时频分析工具箱,希望能对大家有所帮助啊」· M 代码 · 共 44 行

function coef=spreadfun(T)
%SPREADFUN  Spreading function.
%   Usage:  c=spreadfun(T);
%
%   c=SPREADFUN(T) computes the symbol c of the spreading operator
%   that has the same action as the matrix T. 
%
%   SEE ALSO:  SPREADOP, TCONV, SPREADINV, SPREADADJ

% 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/>.


error(nargchk(1,1,nargin));

if ndims(T)>2 || size(T,1)~=size(T,2)
    error('Input symbol T must be a square matrix.');
end;

L=size(T,1);

coef=zeros(L);
for ii=0:L-1
    for jj=0:L-1
        coef(ii+1,jj+1)=T(ii+1,mod(ii-jj,L)+1);
    end;
end;

coef=ifft(coef)*L;

% Scale.
coef=coef/L;