in src/main/java/org/apache/datasketches/hive/tuple/ArrayOfDoublesSketchToMeansUDF.java [47:62]
public List<Double> evaluate(final BytesWritable serializedSketch) {
if (serializedSketch == null) { return null; }
final ArrayOfDoublesSketch sketch = ArrayOfDoublesSketches.wrapSketch(
BytesWritableHelper.wrapAsMemory(serializedSketch));
if (sketch.getRetainedEntries() < 1) {
return null;
}
final SummaryStatistics[] summaries = ArrayOfDoublesSketchStats.sketchToSummaryStatistics(sketch);
final List<Double> means = new ArrayList<>(sketch.getNumValues());
for (int i = 0; i < sketch.getNumValues(); i++) {
means.add(summaries[i].getMean());
}
return means;
}