org.apache.hadoop.io.FloatWritable Java Examples

@Test
public void completeModeDoubleValuesExplicitParameters() throws Exception {
  ObjectInspector[] inspectors = new ObjectInspector[] { doubleInspector, intConstantInspector, floatConstantInspector, longConstantInspector };
  GenericUDAFParameterInfo info = new SimpleGenericUDAFParameterInfo(inspectors, false, false, false);
  try (GenericUDAFEvaluator eval = new DataToSketchUDAF().getEvaluator(info)) {
    ObjectInspector resultInspector = eval.init(Mode.COMPLETE, inspectors);
    checkFinalResultInspector(resultInspector);

    final long seed = 2;
    UnionState state = (UnionState) eval.getNewAggregationBuffer();
    eval.iterate(state, new Object[] {new DoubleWritable(1), new IntWritable(16), new FloatWritable(0.99f), new LongWritable(seed)});
    eval.iterate(state, new Object[] {new DoubleWritable(2), new IntWritable(16), new FloatWritable(0.99f), new LongWritable(seed)});

    Object result = eval.terminate(state);
    Assert.assertNotNull(result);
    Assert.assertTrue(result instanceof BytesWritable);
    Sketch resultSketch = Sketches.wrapSketch(BytesWritableHelper.wrapAsMemory((BytesWritable) result), seed);
    // because of sampling probability < 1
    Assert.assertTrue(resultSketch.isEstimationMode());
    Assert.assertEquals(resultSketch.getEstimate(), 2.0, 0.05);
  }
}
 

public void testIterable() throws Exception {
  Random r = new Random();
  Writable[] writs = {
    new BooleanWritable(r.nextBoolean()),
    new FloatWritable(r.nextFloat()),
    new FloatWritable(r.nextFloat()),
    new IntWritable(r.nextInt()),
    new LongWritable(r.nextLong()),
    new BytesWritable("dingo".getBytes()),
    new LongWritable(r.nextLong()),
    new IntWritable(r.nextInt()),
    new BytesWritable("yak".getBytes()),
    new IntWritable(r.nextInt())
  };
  TupleWritable t = new TupleWritable(writs);
  for (int i = 0; i < 6; ++i) {
    t.setWritten(i);
  }
  verifIter(writs, t, 0);
}
 

/**
 * Set the progress of the current task.
 * *Note: Works only when using a Virtual Input Format
 *
 * @param value value of the progress must lie within [0.0, 1.0]
 */
public static void setProgress(float value)
{
    if (PhaseContext.isIntialized())
    {
        final MapContext mapContext = PhaseContext.getMapContext();
        try
        {
            final FloatWritable progress = (FloatWritable) mapContext.getCurrentKey();
            progress.set(value);
            mapContext.nextKeyValue();
        }
        catch (Exception e)
        {
            System.err.println("Unable to report progress in Load Cyclic. Exception: " + e);
            e.printStackTrace();
        }
    }
}
 

/**
 * Outputs the host or domain as key for this record and numInlinks, numOutlinks
 * or score as the value.
 */
public void map(Text key, Node node,
  OutputCollector<Text, FloatWritable> output, Reporter reporter)
  throws IOException {

  float number = 0;
  if (inlinks) {
    number = node.getNumInlinks();
  }
  else if (outlinks) {
    number = node.getNumOutlinks();
  }
  else {
    number = node.getInlinkScore();
  }

  if (host) {
    key.set(URLUtil.getHost(key.toString()));
  } else {
    key.set(URLUtil.getDomainName(key.toString()));
  }

  output.collect(key, new FloatWritable(number));
}
 

public void testWritable() throws Exception {
  Random r = new Random();
  Writable[] writs = {
    new BooleanWritable(r.nextBoolean()),
    new FloatWritable(r.nextFloat()),
    new FloatWritable(r.nextFloat()),
    new IntWritable(r.nextInt()),
    new LongWritable(r.nextLong()),
    new BytesWritable("dingo".getBytes()),
    new LongWritable(r.nextLong()),
    new IntWritable(r.nextInt()),
    new BytesWritable("yak".getBytes()),
    new IntWritable(r.nextInt())
  };
  TupleWritable sTuple = makeTuple(writs);
  ByteArrayOutputStream out = new ByteArrayOutputStream();
  sTuple.write(new DataOutputStream(out));
  ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());
  TupleWritable dTuple = new TupleWritable();
  dTuple.readFields(new DataInputStream(in));
  assertTrue("Failed to write/read tuple", sTuple.equals(dTuple));
}
 

private static final WritableComparable<?> createWritable(DataType type)
{
    switch (type)
    {
    case BOOLEAN:
        return new BooleanWritable();
    case BYTE:
        return new ByteWritable();
    case INT:
        return new IntWritable();
    case LONG:
        return new LongWritable();
    case FLOAT:
        return new FloatWritable();
    case DOUBLE:
        return new DoubleWritable();
    case STRING:
        return new Text();
    default:
        return null;
    }
}
 

/**
 * Flips and collects the url and numeric sort value.
 */
public void reduce(FloatWritable key, Iterator<Text> values,
  OutputCollector<Text, FloatWritable> output, Reporter reporter)
  throws IOException {

  // take the negative of the negative to get original value, sometimes 0
  // value are a little weird
  float val = key.get();
  FloatWritable number = new FloatWritable(val == 0 ? 0 : -val);
  long numCollected = 0;

  // collect all values, this time with the url as key
  while (values.hasNext() && (numCollected < topn)) {
    Text url = WritableUtils.clone(values.next(), conf);
    output.collect(url, number);
    numCollected++;
  }
}
 

@Override
public Object terminatePartial(@SuppressWarnings("deprecation") AggregationBuffer agg)
        throws HiveException {
    PLSAPredictAggregationBuffer myAggr = (PLSAPredictAggregationBuffer) agg;
    if (myAggr.wcList.size() == 0) {
        return null;
    }

    Object[] partialResult = new Object[5];
    partialResult[0] = myAggr.wcList;
    partialResult[1] = myAggr.probMap;
    partialResult[2] = new IntWritable(myAggr.topics);
    partialResult[3] = new FloatWritable(myAggr.alpha);
    partialResult[4] = new DoubleWritable(myAggr.delta);

    return partialResult;
}
 

@Override
public void backward(Iterable<Synapse<FloatWritable, FloatWritable>> messages)
    throws IOException {
  if (!this.isDropped()) {
    float delta = 0;

    for (Synapse<FloatWritable, FloatWritable> m : messages) {
      // Calculates error gradient for each neuron
      delta += (m.getDelta() * m.getWeight());

      // Weight corrections
      float weight = -this.getLearningRate() * m.getDelta()
          * this.getOutput() + this.getMomentumWeight() * m.getPrevWeight();
      this.push(weight);
    }

    this.backpropagate(delta * squashingFunction.applyDerivative(getOutput()));
  } else {
    this.backpropagate(0);
  }
}
 

@Override
public void forward(Iterable<Synapse<FloatWritable, FloatWritable>> messages)
    throws IOException {
  m2 = (isTraining()) ? MathUtils.getBinomial(1, 0.5) : 0.5f;

  if (m2 > 0) {
    float sum = 0;
    for (Synapse<FloatWritable, FloatWritable> m : messages) {
      sum += m.getInput() * m.getWeight();
    }

    this.setDrop(false);
    this.feedforward(squashingFunction.apply(sum) * m2);
  } else {
    this.setDrop(true);
    this.feedforward(0);
  }
}
 

@Test
public void partial1ModeStringKeysExplicitParams() throws Exception {
  ObjectInspector[] inspectors = new ObjectInspector[] { stringInspector, doubleInspector, intInspector, floatInspector };
  GenericUDAFParameterInfo info = new SimpleGenericUDAFParameterInfo(inspectors, false, false, false);
  try (GenericUDAFEvaluator eval = new DataToDoubleSummarySketchUDAF().getEvaluator(info)) {
    ObjectInspector resultInspector = eval.init(Mode.PARTIAL1, inspectors);
    checkIntermediateResultInspector(resultInspector);

    @SuppressWarnings("unchecked")
    State<DoubleSummary> state = (State<DoubleSummary>) eval.getNewAggregationBuffer();
    eval.iterate(state, new Object[] {new Text("a"), new DoubleWritable(1), new IntWritable(32), new FloatWritable(0.99f)});
    eval.iterate(state, new Object[] {new Text("b"), new DoubleWritable(1), new IntWritable(32), new FloatWritable(0.99f)});

    Object result = eval.terminatePartial(state);
    Assert.assertNotNull(result);
    Assert.assertTrue(result instanceof List);
    List<?> r = (List<?>) result;
    Assert.assertEquals(r.size(), 2);
    Assert.assertEquals(((IntWritable) r.get(0)).get(), 32);
    Sketch<DoubleSummary> resultSketch = Sketches.heapifySketch(
        BytesWritableHelper.wrapAsMemory((BytesWritable) r.get(1)), new DoubleSummaryDeserializer());
    // because of sampling probability < 1
    Assert.assertTrue(resultSketch.isEstimationMode());
    Assert.assertEquals(resultSketch.getEstimate(), 2.0, 0.05);
  }
}
 

@Override
public void backward(
    Iterable<Synapse<FloatWritable, FloatWritable>> messages)
    throws IOException {
  float delta = 0;

  if (!this.isDropped()) {
    for (Synapse<FloatWritable, FloatWritable> m : messages) {
      // Calculates error gradient for each neuron
      delta += (m.getDelta() * m.getWeight());

      // Weight corrections
      float weight = -this.getLearningRate() * m.getDelta()
          * this.getOutput() + this.getMomentumWeight() * m.getPrevWeight();
      this.push(weight);
    }
  }

  this.backpropagate(delta * squashingFunction.applyDerivative(getOutput()));
}
 

@Test
public void completeModeDoubleKeysExplicitParams() throws Exception {
  ObjectInspector[] inspectors = new ObjectInspector[] { doubleInspector, doubleInspector, doubleInspector, intInspector, floatInspector };
  GenericUDAFParameterInfo info = new SimpleGenericUDAFParameterInfo(inspectors, false, false, false);
  try (GenericUDAFEvaluator eval = new DataToArrayOfDoublesSketchUDAF().getEvaluator(info)) {
    ObjectInspector resultInspector = eval.init(Mode.COMPLETE, inspectors);
    checkFinalResultInspector(resultInspector);

    ArrayOfDoublesState state = (ArrayOfDoublesState) eval.getNewAggregationBuffer();
    eval.iterate(state, new Object[] {new DoubleWritable(1), new DoubleWritable(1), new DoubleWritable(2), new IntWritable(32), new FloatWritable(0.99f)});
    eval.iterate(state, new Object[] {new DoubleWritable(2), new DoubleWritable(1), new DoubleWritable(2), new IntWritable(32), new FloatWritable(0.99f)});

    Object result = eval.terminate(state);
    Assert.assertNotNull(result);
    Assert.assertTrue(result instanceof BytesWritable);
    ArrayOfDoublesSketch resultSketch = ArrayOfDoublesSketches.wrapSketch(BytesWritableHelper.wrapAsMemory((BytesWritable) result));
    // because of sampling probability < 1
    Assert.assertTrue(resultSketch.isEstimationMode());
    Assert.assertEquals(resultSketch.getEstimate(), 2.0, 0.05);

    eval.reset(state);
    result = eval.terminate(state);
    Assert.assertNull(result);
  }
}
 

private Writable[] makeRandomWritables() {
  Random r = new Random();
  Writable[] writs = {
    new BooleanWritable(r.nextBoolean()),
    new FloatWritable(r.nextFloat()),
    new FloatWritable(r.nextFloat()),
    new IntWritable(r.nextInt()),
    new LongWritable(r.nextLong()),
    new BytesWritable("dingo".getBytes()),
    new LongWritable(r.nextLong()),
    new IntWritable(r.nextInt()),
    new BytesWritable("yak".getBytes()),
    new IntWritable(r.nextInt())
  };
  return writs;
}
 

public void testIterable() throws Exception {
  Random r = new Random();
  Writable[] writs = {
    new BooleanWritable(r.nextBoolean()),
    new FloatWritable(r.nextFloat()),
    new FloatWritable(r.nextFloat()),
    new IntWritable(r.nextInt()),
    new LongWritable(r.nextLong()),
    new BytesWritable("dingo".getBytes()),
    new LongWritable(r.nextLong()),
    new IntWritable(r.nextInt()),
    new BytesWritable("yak".getBytes()),
    new IntWritable(r.nextInt())
  };
  TupleWritable t = new TupleWritable(writs);
  for (int i = 0; i < 6; ++i) {
    t.setWritten(i);
  }
  verifIter(writs, t, 0);
}
 

public void testWritable() throws Exception {
  Random r = new Random();
  Writable[] writs = {
    new BooleanWritable(r.nextBoolean()),
    new FloatWritable(r.nextFloat()),
    new FloatWritable(r.nextFloat()),
    new IntWritable(r.nextInt()),
    new LongWritable(r.nextLong()),
    new BytesWritable("dingo".getBytes()),
    new LongWritable(r.nextLong()),
    new IntWritable(r.nextInt()),
    new BytesWritable("yak".getBytes()),
    new IntWritable(r.nextInt())
  };
  TupleWritable sTuple = makeTuple(writs);
  ByteArrayOutputStream out = new ByteArrayOutputStream();
  sTuple.write(new DataOutputStream(out));
  ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());
  TupleWritable dTuple = new TupleWritable();
  dTuple.readFields(new DataInputStream(in));
  assertTrue("Failed to write/read tuple", sTuple.equals(dTuple));
}
 

private Writable[] makeRandomWritables() {
  Random r = new Random();
  Writable[] writs = {
    new BooleanWritable(r.nextBoolean()),
    new FloatWritable(r.nextFloat()),
    new FloatWritable(r.nextFloat()),
    new IntWritable(r.nextInt()),
    new LongWritable(r.nextLong()),
    new BytesWritable("dingo".getBytes()),
    new LongWritable(r.nextLong()),
    new IntWritable(r.nextInt()),
    new BytesWritable("yak".getBytes()),
    new IntWritable(r.nextInt())
  };
  return writs;
}
 

private static Writable createPrimitive(Object obj, PrimitiveObjectInspector inspector)
        throws SerDeException {
    if (obj == null) {
        return null;
    }
    switch (inspector.getPrimitiveCategory()) {
        case DOUBLE:
            return new DoubleWritable(((DoubleObjectInspector) inspector).get(obj));
        case FLOAT:
            return new FloatWritable(((FloatObjectInspector) inspector).get(obj));
        case INT:
            return new IntWritable(((IntObjectInspector) inspector).get(obj));
        case LONG:
            return new LongWritable(((LongObjectInspector) inspector).get(obj));
        case STRING:
            return new Text(((StringObjectInspector) inspector).getPrimitiveJavaObject(obj));
        case DATE:
            return ((DateObjectInspector) inspector).getPrimitiveWritableObject(obj);
        case TIMESTAMP:
            return ((TimestampObjectInspector) inspector).getPrimitiveWritableObject(obj);
        default:
            throw new SerDeException("Can't serialize primitive : " + inspector.getPrimitiveCategory());
    }
}
 

public void testWritable() throws Exception {
  Random r = new Random();
  Writable[] writs = {
    new BooleanWritable(r.nextBoolean()),
    new FloatWritable(r.nextFloat()),
    new FloatWritable(r.nextFloat()),
    new IntWritable(r.nextInt()),
    new LongWritable(r.nextLong()),
    new BytesWritable("dingo".getBytes()),
    new LongWritable(r.nextLong()),
    new IntWritable(r.nextInt()),
    new BytesWritable("yak".getBytes()),
    new IntWritable(r.nextInt())
  };
  TupleWritable sTuple = makeTuple(writs);
  ByteArrayOutputStream out = new ByteArrayOutputStream();
  sTuple.write(new DataOutputStream(out));
  ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());
  TupleWritable dTuple = new TupleWritable();
  dTuple.readFields(new DataInputStream(in));
  assertTrue("Failed to write/read tuple", sTuple.equals(dTuple));
}
 

@Override
public Vertex<LongWritable, DoubleWritable, FloatWritable>
getCurrentVertex() throws IOException {
    Vertex<LongWritable, DoubleWritable, FloatWritable> vertex =
            getConf().createVertex();
    LongWritable vertexId = new LongWritable(
            (inputSplit.getSplitIndex() * totalRecords) + recordsRead);
    DoubleWritable vertexValue = new DoubleWritable(vertexId.get() * 10d);
    long targetVertexId =
            (vertexId.get() + 1) %
                    (inputSplit.getNumSplits() * totalRecords);
    float edgeValue = vertexId.get() * 100f;
    List<Edge<LongWritable, FloatWritable>> edges = Lists.newLinkedList();
    edges.add(EdgeFactory.create(new LongWritable(targetVertexId),
            new FloatWritable(edgeValue)));
    vertex.initialize(vertexId, vertexValue, edges);
    ++recordsRead;
    if (LOG.isInfoEnabled()) {
        LOG.info("next: Return vertexId=" + vertex.getId().get() +
                ", vertexValue=" + vertex.getValue() +
                ", targetVertexId=" + targetVertexId + ", edgeValue=" + edgeValue);
    }
    return vertex;
}
 

@Test
public void completeModeGivenK() throws Exception {
  ObjectInspector[] inspectors = new ObjectInspector[] { floatInspector, intInspector };
  GenericUDAFParameterInfo info = new SimpleGenericUDAFParameterInfo(inspectors, false, false, false);
  try (GenericUDAFEvaluator eval = new DataToSketchUDAF().getEvaluator(info)) {
    ObjectInspector resultInspector = eval.init(Mode.COMPLETE, inspectors);
    checkResultInspector(resultInspector);

    SketchState state = (SketchState) eval.getNewAggregationBuffer();
    eval.iterate(state, new Object[] { new FloatWritable(1), new IntWritable(400) });
    eval.iterate(state, new Object[] { new FloatWritable(2), new IntWritable(400) });

    BytesWritable bytes = (BytesWritable) eval.terminate(state);
    KllFloatsSketch resultSketch = KllFloatsSketch.heapify(BytesWritableHelper.wrapAsMemory(bytes));
    Assert.assertEquals(resultSketch.getNormalizedRankError(false), KllFloatsSketch.getNormalizedRankError(400, false));
    Assert.assertEquals(resultSketch.getNumRetained(), 2);
    Assert.assertEquals(resultSketch.getMinValue(), 1f);
    Assert.assertEquals(resultSketch.getMaxValue(), 2f);
  }
}
 

/**
 * Tests that after copying a lazy float object, calling materialize on the original and the
 * copy doesn't advance the tree reader twice
 * @throws Exception
 */
@Test
public void TestCopyFloat() throws Exception {
  ReaderWriterProfiler.setProfilerOptions(null);
  OrcLazyFloat lazyFloat = new OrcLazyFloat(new LazyFloatTreeReader(0, 0) {
    int nextCalls = 0;

    @Override
    public Object next(Object previous) throws IOException {
      if (nextCalls == 0) {
        return new FloatWritable(1.0f);
      }

      throw new IOException("next should only be called once");
    }

    @Override
    protected boolean seekToRow(long currentRow) throws IOException {
      return true;
    }
  });

  FloatObjectInspector floatOI = (FloatObjectInspector)
      OrcLazyObjectInspectorUtils.createLazyObjectInspector(TypeInfoFactory.floatTypeInfo);

  OrcLazyFloat lazyFloat2 = (OrcLazyFloat) floatOI.copyObject(lazyFloat);

  Assert.assertEquals(1.0f, ((FloatWritable) lazyFloat.materialize()).get());
  Assert.assertEquals(1.0f, ((FloatWritable) lazyFloat2.materialize()).get());
}
 

@Test
public void partial1ModeStringKeysExplicitParams() throws Exception {
  ObjectInspector[] inspectors = new ObjectInspector[] { stringInspector, doubleInspector, intInspector, floatInspector, stringInspector };
  GenericUDAFParameterInfo info = new SimpleGenericUDAFParameterInfo(inspectors, false, false, false);
  try (GenericUDAFEvaluator eval = new DataToDoubleSummaryWithModeSketchUDAF().getEvaluator(info)) {
    ObjectInspector resultInspector = eval.init(Mode.PARTIAL1, inspectors);
    checkIntermediateResultInspector(resultInspector);

    @SuppressWarnings("unchecked")
    State<DoubleSummary> state = (State<DoubleSummary>) eval.getNewAggregationBuffer();
    eval.iterate(state, new Object[] {new Text("a"), new DoubleWritable(1), new IntWritable(32), new FloatWritable(0.99f), new Text("Min")});
    eval.iterate(state, new Object[] {new Text("b"), new DoubleWritable(2), new IntWritable(32), new FloatWritable(0.99f), new Text("Min")});
    eval.iterate(state, new Object[] {new Text("a"), new DoubleWritable(2), new IntWritable(32), new FloatWritable(0.99f), new Text("Min")});
    eval.iterate(state, new Object[] {new Text("b"), new DoubleWritable(1), new IntWritable(32), new FloatWritable(0.99f), new Text("Min")});

    Object result = eval.terminatePartial(state);
    Assert.assertNotNull(result);
    Assert.assertTrue(result instanceof List);
    List<?> r = (List<?>) result;
    Assert.assertEquals(r.size(), 3);
    Assert.assertEquals(((IntWritable) r.get(0)).get(), 32);
    Assert.assertEquals(((Text) r.get(1)).toString(), DoubleSummary.Mode.Min.toString());
    Sketch<DoubleSummary> resultSketch = Sketches.heapifySketch(
        BytesWritableHelper.wrapAsMemory((BytesWritable) r.get(2)), new DoubleSummaryDeserializer());
    // because of sampling probability < 1
    Assert.assertTrue(resultSketch.isEstimationMode());
    Assert.assertEquals(resultSketch.getEstimate(), 2.0, 0.05);
    SketchIterator<DoubleSummary> it = resultSketch.iterator();
    while (it.next()) {
      Assert.assertEquals(it.getSummary().getValue(), 1.0);
    }
  }
}
 

@Override
public FloatWritable evaluate(DeferredObject[] arguments) throws HiveException {
    List<String> ftvec1 = HiveUtils.asStringList(arguments[0], arg0ListOI);
    List<String> ftvec2 = HiveUtils.asStringList(arguments[1], arg1ListOI);
    float d = 1.f - CosineSimilarityUDF.cosineSimilarity(ftvec1, ftvec2);
    return new FloatWritable(d);
}
 

@Override
public FloatWritable evaluate(DeferredObject[] arguments) throws HiveException {
    List<String> ftvec1 = HiveUtils.asStringList(arguments[0], arg0ListOI);
    List<String> ftvec2 = HiveUtils.asStringList(arguments[1], arg1ListOI);
    float similarity = cosineSimilarity(ftvec1, ftvec2);
    return new FloatWritable(similarity);
}
 

public FloatWritable evaluate(String a, String b, int k) {
    BigInteger ai = new BigInteger(a);
    BigInteger bi = new BigInteger(b);
    int countMatches = k - HammingDistanceUDF.hammingDistance(ai, bi);
    float jaccard = countMatches / (float) k;
    return val(2.f * (jaccard - 0.5f));
}
 

public FloatWritable evaluate(List<Float> Pu, List<Float> Qi, double Bi) throws HiveException {
    if (Pu == null && Qi == null) {
        return new FloatWritable(0.f);
    }
    if (Pu == null) {
        return new FloatWritable((float) Bi);
    } else if (Qi == null) {
        return new FloatWritable(0.f);
    }

    final int PuSize = Pu.size();
    final int QiSize = Qi.size();
    // workaround for TD        
    if (PuSize == 0) {
        if (QiSize == 0) {
            return new FloatWritable(0.f);
        } else {
            return new FloatWritable((float) Bi);
        }
    } else if (QiSize == 0) {
        return new FloatWritable(0.f);
    }

    if (QiSize != PuSize) {
        throw new HiveException("|Pu| " + PuSize + " was not equal to |Qi| " + QiSize);
    }

    float ret = (float) Bi;
    for (int k = 0; k < PuSize; k++) {
        ret += Pu.get(k) * Qi.get(k);
    }
    return new FloatWritable(ret);
}
 

public void write(Writable w) throws IOException {
  if (w instanceof TypedBytesWritable) {
    writeTypedBytes((TypedBytesWritable) w);
  } else if (w instanceof BytesWritable) {
    writeBytes((BytesWritable) w);
  } else if (w instanceof ByteWritable) {
    writeByte((ByteWritable) w);
  } else if (w instanceof BooleanWritable) {
    writeBoolean((BooleanWritable) w);
  } else if (w instanceof IntWritable) {
    writeInt((IntWritable) w);
  } else if (w instanceof VIntWritable) {
    writeVInt((VIntWritable) w);
  } else if (w instanceof LongWritable) {
    writeLong((LongWritable) w);
  } else if (w instanceof VLongWritable) {
    writeVLong((VLongWritable) w);
  } else if (w instanceof FloatWritable) {
    writeFloat((FloatWritable) w);
  } else if (w instanceof DoubleWritable) {
    writeDouble((DoubleWritable) w);
  } else if (w instanceof Text) {
    writeText((Text) w);
  } else if (w instanceof ArrayWritable) {
    writeArray((ArrayWritable) w);
  } else if (w instanceof MapWritable) {
    writeMap((MapWritable) w);
  } else if (w instanceof SortedMapWritable) {
    writeSortedMap((SortedMapWritable) w);
  } else if (w instanceof Record) {
    writeRecord((Record) w);
  } else {
    writeWritable(w); // last resort
  }
}
 

public FloatWritable terminate() {
    if (partial == null) {
        return null;
    }
    if (partial.sum_inv_covar == 0.f) {// avoid null division
        return new FloatWritable(0.f);
    }
    float mean = (1.f / partial.sum_inv_covar) * partial.sum_mean_div_covar;
    return new FloatWritable(mean);
}
 

public static Writable toWritable(Object object) {
    if (object == null) {
        return null; //return NullWritable.get();
    }
    if (object instanceof Writable) {
        return (Writable) object;
    }
    if (object instanceof String) {
        return new Text((String) object);
    }
    if (object instanceof Long) {
        return new VLongWritable((Long) object);
    }
    if (object instanceof Integer) {
        return new VIntWritable((Integer) object);
    }
    if (object instanceof Byte) {
        return new ByteWritable((Byte) object);
    }
    if (object instanceof Double) {
        return new DoubleWritable((Double) object);
    }
    if (object instanceof Float) {
        return new FloatWritable((Float) object);
    }
    if (object instanceof Boolean) {
        return new BooleanWritable((Boolean) object);
    }
    if (object instanceof byte[]) {
        return new BytesWritable((byte[]) object);
    }
    return new BytesWritable(object.toString().getBytes());
}