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Declarative Machine Learning
/*
* Licensed to the Apache Software Foundation (ASF) under one
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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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* under the License.
*/
package org.apache.sysml.runtime.instructions.spark.functions;
import org.apache.spark.api.java.function.Function;
import org.apache.sysml.runtime.DMLRuntimeException;
import org.apache.sysml.runtime.functionobjects.CM;
import org.apache.sysml.runtime.functionobjects.KahanPlus;
import org.apache.sysml.runtime.instructions.cp.CM_COV_Object;
import org.apache.sysml.runtime.instructions.cp.KahanObject;
import org.apache.sysml.runtime.matrix.data.WeightedCell;
import org.apache.sysml.runtime.matrix.operators.AggregateOperator;
import org.apache.sysml.runtime.matrix.operators.CMOperator;
import org.apache.sysml.runtime.matrix.operators.Operator;
public class PerformGroupByAggInReducer implements Function, WeightedCell>
{
private static final long serialVersionUID = 8160556441153227417L;
Operator op;
public PerformGroupByAggInReducer(Operator op) {
this.op = op;
}
@Override
public WeightedCell call(Iterable kv)
throws Exception
{
WeightedCell outCell = new WeightedCell();
CM_COV_Object cmObj = new CM_COV_Object();
if(op instanceof CMOperator) //everything except sum
{
cmObj.reset();
CM lcmFn = CM.getCMFnObject(((CMOperator) op).aggOpType); // cmFn.get(key.getTag());
if( ((CMOperator) op).isPartialAggregateOperator() ) {
throw new DMLRuntimeException("Incorrect usage, should have used PerformGroupByAggInCombiner");
}
else //forward tuples to reducer
{
for(WeightedCell value : kv)
lcmFn.execute(cmObj, value.getValue(), value.getWeight());
outCell.setValue(cmObj.getRequiredResult(op));
outCell.setWeight(1);
}
}
else if(op instanceof AggregateOperator) //sum
{
AggregateOperator aggop=(AggregateOperator) op;
if( aggop.correctionExists ) {
KahanObject buffer=new KahanObject(aggop.initialValue, 0);
KahanPlus.getKahanPlusFnObject();
//partial aggregate with correction
for(WeightedCell value : kv)
aggop.increOp.fn.execute(buffer, value.getValue()*value.getWeight());
outCell.setValue(buffer._sum);
outCell.setWeight(1);
}
else //no correction
{
double v = aggop.initialValue;
//partial aggregate without correction
for(WeightedCell value : kv)
v=aggop.increOp.fn.execute(v, value.getValue()*value.getWeight());
outCell.setValue(v);
outCell.setWeight(1);
}
}
else
throw new DMLRuntimeException("Unsupported operator in grouped aggregate instruction:" + op);
return outCell;
}
}