wolffd@0: % makro_prepare_comparison
wolffd@0: 
wolffd@0: % ---
wolffd@0: % re_index the comparison song ids
wolffd@0: % ---
wolffd@0: comparison_ids = unique([comparison(:,1); comparison(:,2); comparison(:,3)]);
wolffd@0: 
wolffd@0: for i = 1:3
wolffd@0:     for j = 1:numel(comparison_ids)
wolffd@0:         
wolffd@0:         comparison(comparison(:,i) == comparison_ids(j),i) = j;
wolffd@0:     end
wolffd@0: end
wolffd@0: