function W=params_to_W(P,N_in);
%W=params_to_W(P,N_in);
%decodes square W matrix from parameter vector
%
%Copyright (c) 2009, Travis Wiens
%All rights reserved.
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%Redistribution and use in source and binary forms, with or without
%modification, are permitted provided that the following conditions are
%met:
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% notice, this list of conditions and the following disclaimer.
% * Redistributions in binary form must reproduce the above copyright
% notice, this list of conditions and the following disclaimer in
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%THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
%AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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%ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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%INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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% contact Travis at travis.mlfx@nutaksas.com
if nargin<2
W=reshape(P,sqrt(numel(P)),[]);
else
N=round(max(roots([1 -N_in -numel(P)])));
W=zeros(N);
W((N_in+1):end,:)=reshape(P,N-N_in,N);
end
