comparison src/matlab/prune_corpus.m @ 0:c52bc3e8d3ad tip

user: boblsturm
branch 'default'
added README.md
added assets/.DS_Store
added assets/playButton.jpg
added assets/stopButton.png
added assets/swapButton.jpg
added data/.DS_Store
added data/fiveoctaves.mp3
added data/glock2.wav
added data/sinScale.mp3
added data/speech_female.mp3
added data/sweep.wav
added nimfks.m.lnk
added src/.DS_Store
added src/matlab/.DS_Store
added src/matlab/AnalysisCache.m
added src/matlab/CSS.m
added src/matlab/DataHash.m
added src/matlab/ExistsInCache.m
added src/matlab/KLDivCost.m
added src/matlab/LoadFromCache.m
added src/matlab/SA_B_NMF.m
added src/matlab/SaveInCache.m
added src/matlab/Sound.m
added src/matlab/SynthesisCache.m
added src/matlab/chromagram_E.m
added src/matlab/chromagram_IF.m
added src/matlab/chromagram_P.m
added src/matlab/chromsynth.m
added src/matlab/computeSTFTFeat.m
added src/matlab/controller.m
added src/matlab/decibelSliderReleaseCallback.m
added src/matlab/drawClickCallBack.m
added src/matlab/fft2chromamx.m
added src/matlab/hz2octs.m
added src/matlab/ifgram.m
added src/matlab/ifptrack.m
added src/matlab/istft.m
added src/matlab/nimfks.fig
added src/matlab/nimfks.m
added src/matlab/nmfFn.m
added src/matlab/nmf_beta.m
added src/matlab/nmf_divergence.m
added src/matlab/nmf_euclidean.m
added src/matlab/prune_corpus.m
added src/matlab/rot_kernel.m
added src/matlab/templateAdditionResynth.m
added src/matlab/templateDelCb.m
added src/matlab/templateScrollCb.m

+function [ Y, PrunedFrames, KeepCorpusFrames ] = prune_corpus( target, corpus, reduction_coef )
+
+    if reduction_coef == 1
+        Y = corpus;
+        PrunedFrames = [];
+        KeepCorpusFrames = [];
+        return;
+    end
+    [targetRows, targetCols]= size( target );
+    [corpusRows, corpusCols]= size( corpus );
+    
+    % Matrix: distances of every target frame to every other target frame
+    % i.e. Self-similarity matrix
+    TargetSelfSimMat = zeros(targetCols);
+    
+    % Matrix: distances of every target frame to every corpus frame
+    % Matrix( i, j ) = Similarity of corpus frame i to target frame j
+%     TargetToCorpSimMat = -1*ones(WCols, targetCols);
+    
+    % Calculate self-similarity of target (euclidean dist)
+    X2 = sum(target.^2,1);
+    TargetSelfSimMat = bsxfun(@plus,X2,X2')-2*(target'*target);
+%     TargetSelfSimMat = exp(-(1/10) * DistanceMat);
+    
+    % Calculate the distance between each corpus frame to first target
+    % frame
+    KeepCorpusFrames = [];
+    RemainingTargetFrames = 1:targetCols;
+    RemainingCorpusFrames = 1:corpusCols;
+    
+    while ~isempty(RemainingTargetFrames)
+        Dist = repmat(target(:,RemainingTargetFrames(1)),1, ...
+            length(RemainingCorpusFrames)) - corpus(:,RemainingCorpusFrames);
+        Distances = sum(Dist.^2,1);
+        % compute mean distances
+        meanDistance = mean(Distances);
+        
+        % find those corpus frames closer than reduction_coef of mean
+        idxcorpuskeep = Distances < reduction_coef*meanDistance;
+        KeepCorpusFrames = [KeepCorpusFrames RemainingCorpusFrames(idxcorpuskeep)];
+        
+        % find those target frames within twice that to next frame
+        distancetonext = TargetSelfSimMat(RemainingTargetFrames(1)+1,RemainingTargetFrames(1));
+        idxtarget = TargetSelfSimMat(RemainingTargetFrames,RemainingTargetFrames(1)) ...
+            < 2*distancetonext;
+        
+        if ~any( idxtarget ) && distancetonext == 0
+            idxtarget = RemainingTargetFrames(2);
+        end
+        
+        % shrink corpus
+        RemainingCorpusFrames = RemainingCorpusFrames(~idxcorpuskeep);
+        
+        % shrink target frames index
+        RemainingTargetFrames = RemainingTargetFrames(~idxtarget);
+        
+        fprintf( '%d remaining frames...\n', size( RemainingTargetFrames ) );
+    end
+    
+KeepCorpusFrames = sort( KeepCorpusFrames );
+Y = corpus( :, KeepCorpusFrames );
+PrunedFrames = setdiff( 1:corpusCols, KeepCorpusFrames );
+
+fprintf( 'Pruned %d frames...\n', size( PrunedFrames ) );
+
+end