Ejemplo n.º 1
0
  public List<Polygon> compute() {
    // Compute delaunay triangulation:
    delaunay = (new SweepHullDelaunay2D(points)).getDelaunay();

    List<Polygon> polys = new ArrayList<>();

    // Working data
    long[] used = BitsUtil.zero(delaunay.size());
    List<double[]> cur = new ArrayList<>();

    for (int i = 0 /* = used.nextClearBit(0) */;
        i < delaunay.size() && i >= 0;
        i = BitsUtil.nextClearBit(used, i + 1)) {
      if (!BitsUtil.get(used, i)) {
        BitsUtil.setI(used, i);
        SweepHullDelaunay2D.Triangle tri = delaunay.get(i);
        if (tri.r2 <= alpha2) {
          // Check neighbors
          processNeighbor(cur, used, i, tri.ab, tri.b);
          processNeighbor(cur, used, i, tri.bc, tri.c);
          processNeighbor(cur, used, i, tri.ca, tri.a);
        }
        if (cur.size() > 0) {
          polys.add(new Polygon(cur));
          cur = new ArrayList<>();
        }
      }
    }

    return polys;
  }
Ejemplo n.º 2
0
 /**
  * Select or deselect a row.
  *
  * @param rnum Row to select
  * @param set Value to set
  */
 protected void selectRow(int rnum, boolean set) {
   if (set) {
     BitsUtil.setI(rows, rnum);
     rowcard++;
   } else {
     BitsUtil.clearI(rows, rnum);
     rowcard--;
   }
 }
Ejemplo n.º 3
0
 /**
  * Select or deselect a column.
  *
  * @param cnum Column to select
  * @param set Value to set
  */
 protected void selectColumn(int cnum, boolean set) {
   if (set) {
     BitsUtil.setI(cols, cnum);
     colcard++;
   } else {
     BitsUtil.clearI(cols, cnum);
     colcard--;
   }
 }
Ejemplo n.º 4
0
  @Override
  public long[] getVisibleDimensions2D() {
    final int dim = proj.getDimensionality();
    long[] actDim = BitsUtil.zero(dim);
    double[] vScale = new double[dim];
    for (int d = 0; d < dim; d++) {
      Arrays.fill(vScale, 0);
      vScale[d] = 1;
      double[] vRender = fastProjectScaledToRenderSpace(vScale);

      // TODO: Can't we do this by inspecting the projection matrix directly?
      if (vRender[0] > 0.0 || vRender[0] < 0.0 || vRender[1] != 0) {
        BitsUtil.setI(actDim, d);
      }
    }
    return actDim;
  }
Ejemplo n.º 5
0
  /**
   * Main loop of OUTRES. Run for each object
   *
   * @param s start dimension
   * @param subspace Current subspace
   * @param id Current object ID
   * @param kernel Kernel
   * @return Score
   */
  public double outresScore(
      final int s, long[] subspace, DBIDRef id, KernelDensityEstimator kernel) {
    double score = 1.0; // Initial score is 1.0
    final SubspaceEuclideanDistanceFunction df = new SubspaceEuclideanDistanceFunction(subspace);
    MeanVariance meanv = new MeanVariance();

    for (int i = s; i < kernel.dim; i++) {
      if (BitsUtil.get(subspace, i)) { // TODO: needed? Or should we always start
        // with i=0?
        continue;
      }
      BitsUtil.setI(subspace, i);
      df.setSelectedDimensions(subspace);
      final double adjustedEps = kernel.adjustedEps(kernel.dim);
      // Query with a larger window, to also get neighbors of neighbors
      // Subspace euclidean is metric!
      final double range = adjustedEps * 2.;
      RangeQuery<V> rq = QueryUtil.getRangeQuery(kernel.relation, df, range);

      DoubleDBIDList neighc = rq.getRangeForDBID(id, range);
      DoubleDBIDList neigh = refineRange(neighc, adjustedEps);
      if (neigh.size() > 2) {
        // Relevance test
        if (relevantSubspace(subspace, neigh, kernel)) {
          final double density = kernel.subspaceDensity(subspace, neigh);
          // Compute mean and standard deviation for densities of neighbors.
          meanv.reset();
          for (DoubleDBIDListIter neighbor = neigh.iter(); neighbor.valid(); neighbor.advance()) {
            DoubleDBIDList n2 = subsetNeighborhoodQuery(neighc, neighbor, df, adjustedEps, kernel);
            meanv.put(kernel.subspaceDensity(subspace, n2));
          }
          final double deviation = (meanv.getMean() - density) / (2. * meanv.getSampleStddev());
          // High deviation:
          if (deviation >= 1) {
            score *= (density / deviation);
          }
          // Recursion
          score *= outresScore(i + 1, subspace, id, kernel);
        }
      }
      BitsUtil.clearI(subspace, i);
    }
    return score;
  }
Ejemplo n.º 6
0
 private void processNeighbor(List<double[]> cur, long[] used, int i, int ab, int b) {
   if (ab >= 0) {
     if (BitsUtil.get(used, ab)) {
       return;
     }
     BitsUtil.setI(used, ab);
     final SweepHullDelaunay2D.Triangle next = delaunay.get(ab);
     if (next.r2 < alpha2) {
       // Continue where we left off...
       if (next.ab == i) {
         processNeighbor(cur, used, ab, next.bc, next.c);
         processNeighbor(cur, used, ab, next.ca, next.a);
       } else if (next.bc == i) {
         processNeighbor(cur, used, ab, next.ca, next.a);
         processNeighbor(cur, used, ab, next.ab, next.b);
       } else if (next.ca == i) {
         processNeighbor(cur, used, ab, next.ab, next.b);
         processNeighbor(cur, used, ab, next.bc, next.c);
       }
       return;
     }
   }
   cur.add(points.get(b));
 }
Ejemplo n.º 7
0
 protected void invertRow(int rnum, boolean b) {
   BitsUtil.setI(irow, rnum);
 }
Ejemplo n.º 8
0
  /**
   * Performs a single run of FastDOC, finding a single cluster.
   *
   * @param database Database context
   * @param relation used to get actual values for DBIDs.
   * @param S The set of points we're working on.
   * @param d Dimensionality of the data set we're currently working on.
   * @param r Size of random samples.
   * @param m Number of inner iterations (per seed point).
   * @param n Number of outer iterations (seed points).
   * @return a cluster, if one is found, else <code>null</code>.
   */
  private Cluster<SubspaceModel> runFastDOC(
      Database database, Relation<V> relation, ArrayModifiableDBIDs S, int d, int n, int m, int r) {
    // Relevant attributes of highest cardinality.
    long[] D = null;
    // The seed point for the best dimensions.
    DBIDVar dV = DBIDUtil.newVar();

    // Inform the user about the progress in the current iteration.
    FiniteProgress iprogress =
        LOG.isVerbose()
            ? new FiniteProgress("Iteration progress for current cluster", m * n, LOG)
            : null;

    Random random = rnd.getSingleThreadedRandom();

    DBIDArrayIter iter = S.iter();
    outer:
    for (int i = 0; i < n; ++i) {
      // Pick a random seed point.
      iter.seek(random.nextInt(S.size()));

      for (int j = 0; j < m; ++j) {
        // Choose a set of random points.
        DBIDs randomSet = DBIDUtil.randomSample(S, r, random);

        // Initialize cluster info.
        long[] nD = BitsUtil.zero(d);

        // Test each dimension.
        for (int k = 0; k < d; ++k) {
          if (dimensionIsRelevant(k, relation, randomSet)) {
            BitsUtil.setI(nD, k);
          }
        }

        if (D == null || BitsUtil.cardinality(nD) > BitsUtil.cardinality(D)) {
          D = nD;
          dV.set(iter);

          if (BitsUtil.cardinality(D) >= d_zero) {
            if (iprogress != null) {
              iprogress.setProcessed(iprogress.getTotal(), LOG);
            }
            break outer;
          }
        }
        LOG.incrementProcessed(iprogress);
      }
    }
    LOG.ensureCompleted(iprogress);

    // If no relevant dimensions were found, skip it.
    if (D == null || BitsUtil.cardinality(D) == 0) {
      return null;
    }

    // Get all points in the box.
    SubspaceMaximumDistanceFunction df = new SubspaceMaximumDistanceFunction(D);
    DistanceQuery<V> dq = database.getDistanceQuery(relation, df);
    RangeQuery<V> rq = database.getRangeQuery(dq, DatabaseQuery.HINT_SINGLE);

    // TODO: add filtering capabilities into query API!
    DBIDs C = DBIDUtil.intersection(S, rq.getRangeForDBID(dV, w));

    // If we have a non-empty cluster, return it.
    return (C.size() > 0) ? makeCluster(relation, C, D) : null;
  }
Ejemplo n.º 9
0
  /**
   * Performs a single run of DOC, finding a single cluster.
   *
   * @param database Database context
   * @param relation used to get actual values for DBIDs.
   * @param S The set of points we're working on.
   * @param d Dimensionality of the data set we're currently working on.
   * @param r Size of random samples.
   * @param m Number of inner iterations (per seed point).
   * @param n Number of outer iterations (seed points).
   * @param minClusterSize Minimum size a cluster must have to be accepted.
   * @return a cluster, if one is found, else <code>null</code>.
   */
  private Cluster<SubspaceModel> runDOC(
      Database database,
      Relation<V> relation,
      ArrayModifiableDBIDs S,
      final int d,
      int n,
      int m,
      int r,
      int minClusterSize) {
    // Best cluster for the current run.
    DBIDs C = null;
    // Relevant attributes for the best cluster.
    long[] D = null;
    // Quality of the best cluster.
    double quality = Double.NEGATIVE_INFINITY;

    // Bounds for our cluster.
    // ModifiableHyperBoundingBox bounds = new ModifiableHyperBoundingBox(new
    // double[d], new double[d]);

    // Weights for distance (= rectangle query)
    SubspaceMaximumDistanceFunction df = new SubspaceMaximumDistanceFunction(BitsUtil.zero(d));
    DistanceQuery<V> dq = database.getDistanceQuery(relation, df);
    RangeQuery<V> rq = database.getRangeQuery(dq);

    // Inform the user about the progress in the current iteration.
    FiniteProgress iprogress =
        LOG.isVerbose()
            ? new FiniteProgress("Iteration progress for current cluster", m * n, LOG)
            : null;

    Random random = rnd.getSingleThreadedRandom();
    DBIDArrayIter iter = S.iter();

    for (int i = 0; i < n; ++i) {
      // Pick a random seed point.
      iter.seek(random.nextInt(S.size()));

      for (int j = 0; j < m; ++j) {
        // Choose a set of random points.
        DBIDs randomSet = DBIDUtil.randomSample(S, r, random);

        // Initialize cluster info.
        long[] nD = BitsUtil.zero(d);

        // Test each dimension and build bounding box.
        for (int k = 0; k < d; ++k) {
          if (dimensionIsRelevant(k, relation, randomSet)) {
            BitsUtil.setI(nD, k);
          }
        }
        if (BitsUtil.cardinality(nD) > 0) {
          // Get all points in the box.
          df.setSelectedDimensions(nD);
          // TODO: add filtering capabilities into query API!
          DBIDs nC = DBIDUtil.intersection(S, rq.getRangeForDBID(iter, w));

          if (LOG.isDebuggingFiner()) {
            LOG.finer(
                "Testing a cluster candidate, |C| = "
                    + nC.size()
                    + ", |D| = "
                    + BitsUtil.cardinality(nD));
          }

          // Is the cluster large enough?
          if (nC.size() < minClusterSize) {
            // Too small.
            if (LOG.isDebuggingFiner()) {
              LOG.finer("... but it's too small.");
            }
          } else {
            // Better cluster than before?
            double nQuality = computeClusterQuality(nC.size(), BitsUtil.cardinality(nD));
            if (nQuality > quality) {
              if (LOG.isDebuggingFiner()) {
                LOG.finer("... and it's the best so far: " + nQuality + " vs. " + quality);
              }
              C = nC;
              D = nD;
              quality = nQuality;
            } else {
              if (LOG.isDebuggingFiner()) {
                LOG.finer("... but we already have a better one.");
              }
            }
          }
        }
        LOG.incrementProcessed(iprogress);
      }
    }
    LOG.ensureCompleted(iprogress);

    return (C != null) ? makeCluster(relation, C, D) : null;
  }