Beispiel #1
0
    @Override
    protected void map(LongWritable key, Text value, Context context)
        throws IOException, InterruptedException {
      String line = value.toString();
      StringTokenizer tokenizer = new StringTokenizer(line, " ");
      int dim = tokenizer.countTokens();
      double[] coords = new double[dim];
      for (int i = 0; i < dim; i++) {
        coords[i] = Double.valueOf(tokenizer.nextToken());
      }
      Point point = new Point(coords);

      Centroid nearest = null;
      double nearestDistance = Double.MAX_VALUE;
      for (Centroid c : centers) {
        double dist = point.euclideanDistance(c);
        if (nearest == null) {
          nearest = c;
          nearestDistance = dist;
        } else {
          if (dist < nearestDistance) {
            nearest = c;
            nearestDistance = dist;
          }
        }
      }
      context.write(nearest, point);
    }
Beispiel #2
0
 public Point deepCopy() {
   Point out = new Point();
   out.n = this.n;
   out.coord = new double[out.n];
   for (int i = 0; i < out.n; i++) {
     out.coord[i] = this.coord[i];
   }
   return out;
 }
  public void map(
      LongWritable key, Point value, OutputCollector<LongWritable, Point> output, Reporter reporter)
      throws IOException {
    double min = value.sumOfSquares(centers.get(0));
    int best = 0;

    for (int index = 1; index < numberOfCenters; ++index) {
      double current = value.sumOfSquares(centers.get(index));

      if (current < min) {
        min = current;
        best = index;
      }
    }

    reporter.incrCounter("NUMBER", "NODES", 1);
    reporter.incrCounter("CENTER", "" + best, 1);

    output.collect(new LongWritable(best), value);
  }
Beispiel #4
0
 @Override
 protected void map(Centroid key, Point value, Context context)
     throws IOException, InterruptedException {
   Centroid nearest = null;
   double nearestDistance = Double.MAX_VALUE;
   for (Centroid c : centers) {
     double dist = value.euclideanDistance(c);
     if (nearest == null) {
       nearest = c;
       nearestDistance = dist;
     } else {
       if (dist < nearestDistance) {
         nearest = c;
         nearestDistance = dist;
       }
     }
   }
   context.write(nearest, value);
 }
Beispiel #5
0
 @Override
 protected void reduce(Centroid key, Iterable<Point> values, Context context)
     throws IOException, InterruptedException {
   ArrayList<Point> points = new ArrayList<Point>();
   points.clear();
   int clusterId = key.id;
   Point newCenter = null;
   for (Point p : values) {
     Point copy = p.deepCopy();
     points.add(copy);
     if (newCenter == null) {
       newCenter = new Point(copy.deepCopy());
     } else {
       newCenter = newCenter.add(copy);
     }
   }
   newCenter = newCenter.div(points.size());
   Centroid center = new Centroid(clusterId, newCenter);
   centers.add(center);
   for (Point p : points) {
     context.write(center, p);
   }
 }
Beispiel #6
0
 @Override
 protected void map(Centroid key, Point value, Context context)
     throws IOException, InterruptedException {
   String out = key.toString() + " " + value.toString();
   context.write(new Text(out), new Text(""));
 }
Beispiel #7
0
 @Override
 public void readFields(DataInput dataInput) throws IOException {
   super.readFields(dataInput);
   this.id = dataInput.readInt();
 }
Beispiel #8
0
 @Override
 public void write(DataOutput dataOutput) throws IOException {
   super.write(dataOutput);
   dataOutput.writeInt(id);
 }