comparison core/magnatagatune/ranking_from_comparison_Stober_all_constraints.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function [r, valididx, clip_ids] = ranking_from_comparison_Stober_all_constraints(comparison, comparison_ids)
+% returns rankings for compared songs.
+% rankings are genrerated using a Multigraph analysis of the comparison
+% data 
+% 
+% r(idx,1) = clip being similar to clip idx
+% r(idx,2) = clip being less similar to clip idx
+% r(idx,3) = weight of this ranking
+%
+% the indices in clipids correspond to the indices in comparison_ids
+
+% create similarity graph
+
+cprint(2, 'Generating Stober Multigraph for Similarity Constraints')
+% Gstob = ClipSimGraphStober();
+% Gstob.random_all_constraints_graph;
+% G = ClipSimGraphMulti(Gstob.to_DiGraph());
+load('comp_SimGraphStob_ac1.mat', 'G');
+
+
+% inverse comparison index
+inv_comparison = sparse(comparison_ids,1, 1:numel(comparison_ids));
+
+% ---
+% derive similarity information: this
+% returns the weights of edges meaning sim(a,b) > sim(a,c)
+% ---   
+[weights, a, b, c] = G.similarities();
+% --- 
+% NOTE: it is yet unclear which index 
+% (the comparison or the mtt clip index) 
+% is best to use
+% 
+% The lines below transform the MTT ids from the graph into comparison ids
+% ---
+a = inv_comparison(a);
+b = inv_comparison(b);
+c = inv_comparison(c);
+
+% ---
+% reformat into ranking: the first 1019 clips are ordered
+% as in comparison_ids. then, clips mentioned more than once 
+% are attached. 
+% ---
+[a, idx] = sort(a);
+b = b(idx);
+c = c(idx);
+
+
+clip_ids = zeros(numel(a), 1);
+
+% ---
+% NOTE: r may grow over its allocated size
+% ---
+r = cell(numel(a),1 );
+
+% keep track of constraints which have been attached
+visited = zeros(1, numel(a));
+for i = 1:numel(comparison_ids)
+    
+    % ---
+    % get first occurence of this index,
+    % and save the data into ranking
+    % ---
+    tmp_idx = find(a == i, 1, 'first');
+    
+    clip_ids(i) = i; % == a(tmp_idx)
+        
+    if ~isempty(tmp_idx)
+        visited(tmp_idx) = true;
+        
+        r{i,1} = b(tmp_idx);
+        r{i,2} = c(tmp_idx);
+        r{i,3} = weights(tmp_idx);
+        
+        valididx(i) = true;
+    else
+        % invalid ranking
+        valididx(i) = false;
+        r{i,3} = 0;
+    end
+end
+
+% ---
+% Now we attach the remaining constraints
+% ---
+remaining = find(~visited);
+clip_ids( numel(comparison_ids)+1 : numel(comparison_ids)+numel(remaining)) = a(remaining);
+
+for i = 1:numel(remaining)
+    r{ numel(comparison_ids)+i, 1} = b(remaining(i));
+    r{ numel(comparison_ids)+i , 2} = c(remaining(i));
+    r{ numel(comparison_ids)+i , 3} = weights(remaining(i));
+end
+
+valididx(numel(comparison_ids)+1 : ...
+    numel(comparison_ids)+numel(remaining)) = true;
+