//// Testing generalization perfroamnce of trained perceptron
 exec perceptronTrain.sce;
 
 function r=randomFlipMatrix(n);
 // returns matrix with components 1 at n random positions of each column 
  r=zeros(156,26);
  for i=1:26
    x=grand(1,'prm',(1:156)');
    r(x(1:n),i)=1;
  end
 endfunction
 
 letterMatrix=rIn;
 for nflip = 1:80;    
    distH=[];
    for trial=1:10;     
       rIn=abs(letterMatrix-randomFlipMatrix(nflip));
       rOut=(wOut*rIn)>0.5;
       distH=[distH,sum(sum((rDes-rOut).^2))/26];
    end
    meanDistH(nflip)=mean(distH);
    stdDistH(nflip)=st_deviation(distH);
 end
figure;
 plot((1:80)',meanDistH);
 errbar((1:80)',meanDistH,stdDistH,stdDistH)
 xlabel('Number of flipped bits')
 ylabel('Average Hamming distance')