wolffd@0: function r = cut_Y(r, valid_idx)
wolffd@0: % disables the invalid parts of the ranking structure Y    
wolffd@0: 
wolffd@0:     % get indices not mentioned
wolffd@0:     u = find(~valid_idx);
wolffd@0:     
wolffd@0:     % clear bad data
wolffd@0:     for i = 1 : numel(u)
wolffd@0:         
wolffd@0:         r{u(i), 1} = [];
wolffd@0:         r{u(i), 2} = [];
wolffd@0:     end
wolffd@0:     
wolffd@0:     % also clear weights if applicable
wolffd@0:     if size(r,2) == 3
wolffd@0:         for i = 1 : numel(u)
wolffd@0:             r{u(i), 3} = 0;
wolffd@0:         end
wolffd@0:     end
wolffd@0: end