wolffd@0: function [r, valididx, clip_ids] = ranking_from_comparison_trivial(comparison, comparison_ids)
wolffd@0: % returns a ranking for each of the compared songs 
wolffd@0: %
wolffd@0: % r(idx,1) =  all indexes which are similar to clip idx
wolffd@0: % r(idx,2) = all indexes which are dissimilar to clip idx
wolffd@0: %
wolffd@0: % if onlyvalid is set to true, only the transitive hull of 
wolffd@0: % clips having sim and dissim values will be output
wolffd@0: 
wolffd@0: % ---
wolffd@0: % in comparison, the outlying piece is highlighted. 
wolffd@0: % thus, we naively consider that
wolffd@0: % a. both of the remaining pieces are more similar to each other.
wolffd@0: % b. the outlier is dissimilar to both of the other pieces
wolffd@0: % ---
wolffd@0: 
wolffd@0: [outsort, outidx] = sort(comparison(:,4:6),2,'ascend');
wolffd@0: 
wolffd@0: r = cell(numel(comparison_ids), 2);
wolffd@0: s = zeros(numel(comparison_ids), 2); % score for rankings
wolffd@0: for i = 1:size(comparison, 1)
wolffd@0: 
wolffd@0:     % get the three relevant comparison ids
wolffd@0: 
wolffd@0:     pos = comparison(i, outidx(i,1:3));
wolffd@0:     vals = outsort(i,:);
wolffd@0:     
wolffd@0:     % ---
wolffd@0:     % each of the three clips will be evaluated based on its position
wolffd@0:     % the last clip is the potential outlyier
wolffd@0:     % ---
wolffd@0:     
wolffd@0:     % ---
wolffd@0:     % usual case: two small values and a last outlie
wolffd@0:     % ---
wolffd@0:     if vals(2) ~= vals(3)
wolffd@0:         
wolffd@0:         
wolffd@0:         % ---
wolffd@0:         % first (most common) clip:
wolffd@0:         % the second clip is more similar than the third one
wolffd@0:         % ---
wolffd@0:         r{pos(1),1} = cat(1, r{pos(1),1}, pos(2));  % similar
wolffd@0:         r{pos(1),2} = cat(1, r{pos(1),2}, pos(3));  % dissimilar
wolffd@0: %     else
wolffd@0: %         
wolffd@0: %         % ok, both seem more dissimilar to clip 1
wolffd@0: %         r{pos(1),2} = cat(1, r{pos(1),1}, pos(2));  % both dissimilar
wolffd@0: %         r{pos(1),2} = cat (1, r{pos(1),2}, pos(3));  % dissimilar
wolffd@0:     end
wolffd@0:     
wolffd@0:     if vals(3) ~= vals(1)
wolffd@0:         % ---
wolffd@0:         % the second clip is more similar to the first than 
wolffd@0:         % the third
wolffd@0:         % ---
wolffd@0:         r{pos(2),1} = cat(1, r{pos(2),1}, pos(1));
wolffd@0:         r{pos(2),2} = cat(1, r{pos(2),2}, pos(3));
wolffd@0:     
wolffd@0:         % ---
wolffd@0:         % the third clip is not similar to any of the former 
wolffd@0:         % NOTE: we avoid this information as it possibly leads 
wolffd@0:         % to some contradictionary statements
wolffd@0:         % ---
wolffd@0:             r{pos(3),2} = cat(1, r{pos(3),2}, pos(1));
wolffd@0:             r{pos(3),2} = cat(1, r{pos(3),2}, pos(2));
wolffd@0:     end
wolffd@0:     
wolffd@0: 
wolffd@0: end
wolffd@0: 
wolffd@0: % ---
wolffd@0: % we cleanup r and 
wolffd@0: % run basic checks on emptiness and paradox assumptions
wolffd@0: % ---
wolffd@0: valididx = zeros(size(r,1), 1);
wolffd@0: for i = 1:size(r, 1)
wolffd@0:     
wolffd@0:     % make unique
wolffd@0:     r{i,1} = unique(r{i,1});
wolffd@0:     r{i,2} = unique(r{i,2});
wolffd@0:     
wolffd@0:     % check
wolffd@0:     valididx(i) = ~isempty(r{i,1}) && ~isempty(r{i,2}) && ...
wolffd@0:         isempty(intersect(r{i,1}, r{i,2}));
wolffd@0: end
wolffd@0: 
wolffd@0: valididx = logical(valididx);
wolffd@0: clip_ids = 1:numel(comparison_ids);
wolffd@0: