Examples of MeanVariance

   */
  public OutlierResult run(Database database, Relation<N> nrel, Relation<? extends NumberVector<?, ?>> relation) {
    final NeighborSetPredicate npred = getNeighborSetPredicateFactory().instantiate(nrel);
    WritableDoubleDataStore scores = DataStoreUtil.makeDoubleStorage(relation.getDBIDs(), DataStoreFactory.HINT_STATIC);


    MeanVariance zmv = new MeanVariance();
    for(DBID id : relation.iterDBIDs()) {
      DBIDs neighbors = npred.getNeighborDBIDs(id);
      // Compute Mean of neighborhood
      Mean localmean = new Mean();
      for(DBID n : neighbors) {
        if(id.equals(n)) {
          continue;
        }
        else {
          localmean.put(relation.get(n).doubleValue(1));
        }
      }
      final double localdiff;
      if(localmean.getCount() > 0) {
        localdiff = relation.get(id).doubleValue(1) - localmean.getMean();
      }
      else {
        localdiff = 0.0;
      }
      scores.putDouble(id, localdiff);
      zmv.put(localdiff);
    }


    // Normalize scores using mean and variance
    DoubleMinMax minmax = new DoubleMinMax();
    for(DBID id : relation.iterDBIDs()) {
      double score = Math.abs(scores.doubleValue(id) - zmv.getMean()) / zmv.getSampleStddev();
      minmax.put(score);
      scores.putDouble(id, score);
    }


    // Wrap result

          final double r = c.first;
          final double alpha_r = alpha * r;
          // compute n(p_i, \alpha * r) from list (note: alpha_r is different from c!)
          final int n_alphar = elementsAtRadius(cdist, alpha_r);
          // compute \hat{n}(p_i, r, \alpha) and the corresponding \simga_{MDEF}
          MeanVariance mv_n_r_alpha = new MeanVariance();
          for(DistanceResultPair<D> ne : maxneighbors) {
            // Stop at radius r
            if(ne.getDistance().doubleValue() > r) {
              break;
            }
            int rn_alphar = elementsAtRadius(interestingDistances.get(ne.getDBID()), alpha_r);
            mv_n_r_alpha.put(rn_alphar);
          }
          // We only use the average and standard deviation
          final double nhat_r_alpha = mv_n_r_alpha.getMean();
          final double sigma_nhat_r_alpha = mv_n_r_alpha.getNaiveStddev();


          // Redundant divisions removed.
          final double mdef = (nhat_r_alpha - n_alphar); // / nhat_r_alpha;
          final double sigmamdef = sigma_nhat_r_alpha; // / nhat_r_alpha;
          final double mdefnorm = mdef / sigmamdef;

Examples of MeanVariance

Examples of de.lmu.ifi.dbs.elki.math.MeanVariance

Examples of de.lmu.ifi.dbs.elki.math.MeanVariance