private void registerTupleDoubleSummary() {
    SketchDescriptor sd = new SketchDescriptor("tuple_doublesummary");
    sd.register(DATA_TO_SKETCH, org.apache.datasketches.hive.tuple.DataToDoubleSummarySketchUDAF.class);
    //registerUDF(org.apache.datasketches.hive.theta.SketchToStringUDF.class, p + SKETCH_TO_STRING);
    sd.register(UNION_SKETCH, org.apache.datasketches.hive.tuple.UnionDoubleSummarySketchUDAF.class);
    sd.register(SKETCH_TO_ESTIMATE, org.apache.datasketches.hive.tuple.DoubleSummarySketchToEstimatesUDF.class);
    sd.register(SKETCH_TO_PERCENTILE, org.apache.datasketches.hive.tuple.DoubleSummarySketchToPercentileUDF.class);
    sketchClasses.put("tuple_doublesummary", sd);
  }
Registers functions from the DataSketches library as builtin functions.

In an effort to show a more consistent
ql/src/java/org/apache/hadoop/hive/ql/exec/DataSketchesFunctions.java