org.elasticsearch.search.aggregations.metrics.InternalMedianAbsoluteDeviation Maven / Gradle / Ivy
/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.search.aggregations.metrics;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.search.DocValueFormat;
import org.elasticsearch.search.aggregations.InternalAggregation;
import org.elasticsearch.xcontent.XContentBuilder;
import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.Objects;
public class InternalMedianAbsoluteDeviation extends InternalNumericMetricsAggregation.SingleValue implements MedianAbsoluteDeviation {
static double computeMedianAbsoluteDeviation(TDigestState valuesSketch) {
if (valuesSketch.size() == 0) {
return Double.NaN;
} else {
final double approximateMedian = valuesSketch.quantile(0.5);
final TDigestState approximatedDeviationsSketch = new TDigestState(valuesSketch.compression());
valuesSketch.centroids().forEach(centroid -> {
final double deviation = Math.abs(approximateMedian - centroid.mean());
approximatedDeviationsSketch.add(deviation, centroid.count());
});
return approximatedDeviationsSketch.quantile(0.5);
}
}
private final TDigestState valuesSketch;
private final double medianAbsoluteDeviation;
InternalMedianAbsoluteDeviation(String name, Map metadata, DocValueFormat format, TDigestState valuesSketch) {
super(name, metadata);
this.format = Objects.requireNonNull(format);
this.valuesSketch = Objects.requireNonNull(valuesSketch);
this.medianAbsoluteDeviation = computeMedianAbsoluteDeviation(this.valuesSketch);
}
public InternalMedianAbsoluteDeviation(StreamInput in) throws IOException {
super(in);
format = in.readNamedWriteable(DocValueFormat.class);
valuesSketch = TDigestState.read(in);
medianAbsoluteDeviation = in.readDouble();
}
@Override
protected void doWriteTo(StreamOutput out) throws IOException {
out.writeNamedWriteable(format);
TDigestState.write(valuesSketch, out);
out.writeDouble(medianAbsoluteDeviation);
}
@Override
public InternalAggregation reduce(List aggregations, ReduceContext reduceContext) {
final TDigestState valueMerged = new TDigestState(valuesSketch.compression());
for (InternalAggregation aggregation : aggregations) {
final InternalMedianAbsoluteDeviation madAggregation = (InternalMedianAbsoluteDeviation) aggregation;
valueMerged.add(madAggregation.valuesSketch);
}
return new InternalMedianAbsoluteDeviation(name, metadata, format, valueMerged);
}
@Override
public XContentBuilder doXContentBody(XContentBuilder builder, Params params) throws IOException {
final boolean anyResults = valuesSketch.size() > 0;
final Double mad = anyResults ? getMedianAbsoluteDeviation() : null;
builder.field(CommonFields.VALUE.getPreferredName(), mad);
if (format != DocValueFormat.RAW && anyResults) {
builder.field(CommonFields.VALUE_AS_STRING.getPreferredName(), format.format(mad).toString());
}
return builder;
}
@Override
public int hashCode() {
return Objects.hash(super.hashCode(), valuesSketch);
}
@Override
public boolean equals(Object obj) {
if (this == obj) return true;
if (obj == null || getClass() != obj.getClass()) return false;
if (super.equals(obj) == false) return false;
InternalMedianAbsoluteDeviation other = (InternalMedianAbsoluteDeviation) obj;
return Objects.equals(valuesSketch, other.valuesSketch);
}
@Override
public String getWriteableName() {
return MedianAbsoluteDeviationAggregationBuilder.NAME;
}
TDigestState getValuesSketch() {
return valuesSketch;
}
@Override
public double value() {
return getMedianAbsoluteDeviation();
}
@Override
public double getMedianAbsoluteDeviation() {
return medianAbsoluteDeviation;
}
}