/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file 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 "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 org.apache.mahout.h2obindings.ops;
import org.apache.mahout.math.Matrix;
import org.apache.mahout.math.Vector;
import org.apache.mahout.math.DiagonalMatrix;
import org.apache.mahout.h2obindings.drm.H2OBCast;
import org.apache.mahout.h2obindings.drm.H2ODrm;
import water.MRTask;
import water.fvec.Frame;
import water.fvec.Vec;
import water.fvec.Chunk;
import water.fvec.NewChunk;
/**
* Multiple DRM with in-core Matrix
*/
public class TimesRightMatrix {
/**
* Multiply a DRM with an in-core Matrix to create a new DRM.
*
* @param drmA DRM representing matrix A.
* @param B in-core Mahout Matrix.
* @return new DRM containing drmA times B.
*/
public static H2ODrm exec(H2ODrm drmA, Matrix B) {
Frame A = drmA.frame;
Vec keys = drmA.keys;
Frame AinCoreB = null;
if (B instanceof DiagonalMatrix) {
AinCoreB = execDiagonal(A, B.viewDiagonal());
} else {
AinCoreB = execCommon(A, B);
}
return new H2ODrm(AinCoreB, keys);
}
/**
* Multiply Frame A with in-core diagonal Matrix (whose diagonal Vector is d)
*
* A.numCols() == d.size()
*/
private static Frame execDiagonal(final Frame A, Vector d) {
final H2OBCast<Vector> bd = new H2OBCast<Vector>(d);
return new MRTask() {
public void map(Chunk chks[], NewChunk ncs[]) {
Vector D = bd.value();
int chunkSize = chks[0].len();
for (int c = 0; c < ncs.length; c++) {
for (int r = 0; r < chunkSize; r++) {
double v = (chks[c].at0(r) * D.getQuick(c));
ncs[c].addNum(v);
}
}
}
}.doAll(d.size(), A).outputFrame(null, null);
}
/**
* Multiply Frame A with in-core Matrix b
*
* A.numCols() == b.rowSize()
*/
private static Frame execCommon(final Frame A, Matrix b) {
final H2OBCast<Matrix> bb = new H2OBCast<Matrix>(b);
return new MRTask() {
public void map(Chunk chks[], NewChunk ncs[]) {
Matrix B = bb.value();
int chunkSize = chks[0].len();
for (int c = 0; c < ncs.length; c++) {
for (int r = 0; r < chunkSize; r++) {
double v = 0;
for (int i = 0; i < chks.length; i++) {
v += (chks[i].at0(r) * B.getQuick(i, c));
}
ncs[c].addNum(v);
}
}
}
}.doAll(b.columnSize(), A).outputFrame(null, null);
}
}