/*
* 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 water.MRTask;
import water.fvec.Frame;
import water.fvec.Vec;
import water.fvec.Chunk;
import water.fvec.NewChunk;
import water.parser.ValueString;
import org.apache.mahout.h2obindings.H2OHelper;
import org.apache.mahout.h2obindings.drm.H2ODrm;
/**
* R-like rbind like operator, on two DRMs
*/
public class Rbind {
/**
* Combine the rows of two DRMs A and B to create a new DRM.
*
* @param drmA DRM representing matrix A.
* @param drmB DRM representing matrix B.
* @return new DRM containing rows of B below A.
*/
public static H2ODrm exec(H2ODrm drmA, H2ODrm drmB) {
final Frame fra = drmA.frame;
final Vec keysa = drmA.keys;
final Frame frb = drmB.frame;
final Vec keysb = drmB.keys;
// Create new frame and copy A's data at the top, and B's data below.
// Create the frame in the same VectorGroup as A, so A's data does not
// cross the wire during copy. B's data could potentially cross the wire.
Frame frbind = H2OHelper.emptyFrame(fra.numRows() + frb.numRows(), fra.numCols(),
-1, -1, fra.anyVec().group());
Vec keys = null;
MRTask task = new MRTask() {
public void map(Chunk chks[], NewChunk nc) {
Vec A_vecs[] = fra.vecs();
Vec B_vecs[] = frb.vecs();
long A_rows = fra.numRows();
long B_rows = frb.numRows();
long start = chks[0].start();
int chunkSize = chks[0].len();
ValueString vstr = new ValueString();
for (int r = 0; r < chunkSize; r++) {
for (int c = 0; c < chks.length; c++) {
if (r + start < A_rows) {
chks[c].set0(r, A_vecs[c].at(r + start));
if (keysa != null) {
nc.addStr(keysa.atStr(vstr, r + start));
}
} else {
chks[c].set0(r, B_vecs[c].at(r + start - A_rows));
if (keysb != null) {
nc.addStr(keysb.atStr(vstr, r + start - A_rows));
}
}
}
}
}
};
if (keysa == null) {
keys = task.doAll(1, frbind).outputFrame(null, null).anyVec();
} else {
task.doAll(frbind);
}
return new H2ODrm(frbind, keys);
}
}