function nextWords = apriori_gen(words, sortedA)
%-----------------------------------------------------------
% created by Jan Hrdlicka, 16.9.2010
%-----------------------------------------------------------
% Generates next level words(itemsets).
% input is cell array "words" with words (arrays of items represented by numbers)
% and vector of sorted items "sortedA" with size 1xM, where M is number of
% items.
% Size of the cell array "words" is Nx1, where N is number of words. Word
% is vector with size 1xI, where I is number of items in the current word.
    nextWords = {};
    for i = 1:size(words, 2)
        actWord = words{1,i};
        ind = find(sortedA==actWord(end));
        if ind~=length(sortedA)
            for j = sortedA(ind+1:end)
                nextWords{end+1,1} = [actWord j];
            end
        end
    end
end