/** Retrieve transcriptions most similar to the query */
public SearchResult[] retrieveMostSimilar(Signal likelihoodSignal) throws noMetadataException {
if (this.Files == null) {
this.finaliseIndex();
}
ArrayList results = new ArrayList();
// get features
double[] features =
likelihoodSignal.getData()[likelihoodSignal.getColumnIndex(Signal.PROP_LIKELIHOODS)];
double queryRootSquareSum = 0.0;
for (int j = 0; j < features.length; j++) {
queryRootSquareSum += Math.pow(features[j] / featureStds[j], 2.0);
}
queryRootSquareSum = Math.sqrt(queryRootSquareSum);
// iterate through all files
for (int i = 0; i < Files.length; i++) {
float score = 0.0f;
// get features
double[] testFeatures = ((double[]) this.FileLocationToFeaturesMap.get(Files[i]));
// Normalised Cosine distance between likelihoods
double prodSum = 0.0;
double testSum = 0.0;
for (int j = 0; j < features.length; j++) {
prodSum += (features[j] / featureStds[j]) * (testFeatures[j] / featureStds[j]);
testSum += Math.pow(testFeatures[j] / featureStds[j], 2.0);
}
score = (float) (prodSum / (queryRootSquareSum * Math.sqrt(testSum)));
Signal outSig = (Signal) FileLocationToSignalMap.get((String) Files[i]);
results.add(new SearchResult(outSig, score));
}
SearchResult[] outputResults =
(SearchResult[]) results.toArray(new SearchResult[results.size()]);
java.util.Arrays.sort((Object[]) outputResults);
return outputResults;
}
