com.ibm.bi.dml.runtime.instructions.spark.functions.ReplicateVectorFunction.java Source code

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/**
 * (C) Copyright IBM Corp. 2010, 2015
 *
 * Licensed 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 "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
*/

package com.ibm.bi.dml.runtime.instructions.spark.functions;

import java.util.ArrayList;

import org.apache.spark.api.java.function.PairFlatMapFunction;

import scala.Tuple2;

import com.ibm.bi.dml.runtime.matrix.data.MatrixBlock;
import com.ibm.bi.dml.runtime.matrix.data.MatrixIndexes;

public class ReplicateVectorFunction
        implements PairFlatMapFunction<Tuple2<MatrixIndexes, MatrixBlock>, MatrixIndexes, MatrixBlock> {

    private static final long serialVersionUID = -1505557561471236851L;

    private boolean _byRow;
    private long _numReplicas;

    public ReplicateVectorFunction(boolean byRow, long numReplicas) {
        _byRow = byRow;
        _numReplicas = numReplicas;
    }

    @Override
    public Iterable<Tuple2<MatrixIndexes, MatrixBlock>> call(Tuple2<MatrixIndexes, MatrixBlock> arg0)
            throws Exception {
        MatrixIndexes ix = arg0._1();
        MatrixBlock mb = arg0._2();

        //sanity check inputs
        if (_byRow && (ix.getRowIndex() != 1 || mb.getNumRows() > 1)) {
            throw new Exception("Expected a row vector in ReplicateVector");
        }
        if (!_byRow && (ix.getColumnIndex() != 1 || mb.getNumColumns() > 1)) {
            throw new Exception("Expected a column vector in ReplicateVector");
        }

        ArrayList<Tuple2<MatrixIndexes, MatrixBlock>> retVal = new ArrayList<Tuple2<MatrixIndexes, MatrixBlock>>();
        for (int i = 1; i <= _numReplicas; i++) {
            if (_byRow)
                retVal.add(new Tuple2<MatrixIndexes, MatrixBlock>(new MatrixIndexes(i, ix.getColumnIndex()), mb));
            else
                retVal.add(new Tuple2<MatrixIndexes, MatrixBlock>(new MatrixIndexes(ix.getRowIndex(), i), mb));
        }

        return retVal;
    }
}