%--------------------------------------------------------------------------
%      convol is function developped by J.C. COMTE  comtejc@gmail.com
%                              CNC  UMR CNRS 5229.
%                          Last Release  Dec. 2007
%         This work is protected by the CeCILL-C Licence (see below).
%
%
%  X and Y are two vector unidimensional.
%  C is the centered convolution.
%
%
% This software is governed by the [CeCILL|CeCILL-B|CeCILL-C] license under French law and
% abiding by the rules of distribution of free software.  You can  use, 
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% "http://www.cecill.info". 
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%--------------------------------------------------------------------------

function C=convol(X,Y)

  if (size(Y,2)>size(Y,1))
      Y=Y';
  end;
  
 Z=conv(X,Y);
 N=int32(max(size(Y))/2);
 M=int32(max(size(X)));
 C=Z(N:N+M-1);