function vis(Vector,index);
% function vis(Vector,index); - visualises the specified element from
% VECTOR - images in vector format
% INDEX  - the index of the image to be displayed
  
% the dimension of the image is computed
dim = floor(sqrt(size(Vector,1)));

colormap gray;
imagesc(reshape(Vector(:,index),dim,dim)');
axis tight;
shading interp;
set(gca,'Xtick',[]);
set(gca,'Ytick',[]);
