reco_PCA2DL1S.m

function reco_PCA2DL1S(database,iLam)
% Calculate the reconstruction error of 2DPCAL1-S. 

%     Generalized two dimensional principal component analysis by Lp-norm for image analysis
%     Copyright (C) 2015 Jing Wang
% 
%     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/>.

fprintf('reco_PCA2DL1S_par(%s,%d)\n\n',database,iLam);

tic;
load(sprintf('data/%s_noise.mat',database));

nSub=size(x_noise,3);
x_mean=mean(x_noise,3);
x_centered=x_noise-repmat(x_mean,[1,1,nSub]);

sLam=10.^[-3:0.1:3];
nLam=length(sLam);

nPV=30;

lam=sLam(iLam);
W=PCA2DL1S(x_centered,lam,nPV);
err=zeros(nPV,1);
for iPV=1:nPV
    w=W(:,1:iPV);
    
    x_reco=zeros(size(x_noise));
    for iSub=1:nSub
        x_reco(:,:,iSub)=x_centered(:,:,iSub)*w*w'+x_mean;
    end
    temp=x_noise-x_reco;
    
    rsd=0;
    for iSub=nSub/5+1:nSub % only count the differences of normal faces, not all. 1:165
        rsd=rsd+norm(temp(:,:,ix_noise(iSub)),'fro');
    end
    err(iPV,1)=rsd/(nSub/5*4); % there are (80%*n) faces calculated
    
    perct(toc,iPV,nPV);
end
time=toc/60;
save(sprintf('result/reco_PCA2DL1S_%s_iLam%d',database,iLam),'err','time');