package de.lmu.ifi.dbs.elki.datasource.filter;
/*
This file is part of ELKI:
Environment for Developing KDD-Applications Supported by Index-Structures
Copyright (C) 2011
Ludwig-Maximilians-Universität München
Lehr- und Forschungseinheit für Datenbanksysteme
ELKI Development Team
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
import java.util.ArrayList;
import java.util.List;
import de.lmu.ifi.dbs.elki.data.ExternalID;
import de.lmu.ifi.dbs.elki.data.LabelList;
import de.lmu.ifi.dbs.elki.data.type.SimpleTypeInformation;
import de.lmu.ifi.dbs.elki.data.type.TypeUtil;
import de.lmu.ifi.dbs.elki.datasource.bundle.MultipleObjectsBundle;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.AbstractParameterizer;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.OptionID;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.constraints.GreaterEqualConstraint;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameterization.Parameterization;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.IntParameter;
/**
* Class that turns a label column into an external ID column.
*
* @author Erich Schubert
*
* @apiviz.uses LabelList oneway - - «reads»
* @apiviz.has ExternalID oneway - - «produces»
*/
// TODO: use a non-string class for external ids?
public class ExternalIDFilter implements ObjectFilter {
/**
* Optional parameter that specifies the index of the label to be used as
* external Id, must be an integer equal to or greater than 0.
* <p>
* Key: {@code -dbc.externalIdIndex}
* </p>
*/
public static final OptionID EXTERNALID_INDEX_ID = OptionID.getOrCreateOptionID("dbc.externalIdIndex", "The index of the label to be used as external Id.");
/**
* The index of the label to be used as external Id, null if no external id
* index is specified.
*/
private final int externalIdIndex;
/**
* Constructor.
*
* @param externalIdIndex
*/
public ExternalIDFilter(int externalIdIndex) {
super();
this.externalIdIndex = externalIdIndex;
}
@Override
public MultipleObjectsBundle filter(MultipleObjectsBundle objects) {
MultipleObjectsBundle bundle = new MultipleObjectsBundle();
// Find a labellist column
boolean done = false;
boolean keeplabelcol = false;
for(int i = 0; i < objects.metaLength(); i++) {
SimpleTypeInformation<?> meta = objects.meta(i);
// Skip non-labellist columns - or if we already had a labellist
if(done || meta.getRestrictionClass() != LabelList.class) {
bundle.appendColumn(meta, objects.getColumn(i));
continue;
}
done = true;
// We split the label column into two parts
List<ExternalID> eidcol = new ArrayList<ExternalID>(objects.dataLength());
List<LabelList> lblcol = new ArrayList<LabelList>(objects.dataLength());
// Split the column
for(Object obj : objects.getColumn(i)) {
if(obj != null) {
LabelList ll = (LabelList) obj;
eidcol.add(new ExternalID(ll.remove(externalIdIndex)));
lblcol.add(ll);
if(ll.size() > 0) {
keeplabelcol = true;
}
}
else {
eidcol.add(null);
lblcol.add(null);
}
}
bundle.appendColumn(TypeUtil.EXTERNALID, eidcol);
// Only add the label column when it's not empty.
if(keeplabelcol) {
bundle.appendColumn(meta, lblcol);
}
}
return bundle;
}
/**
* Parameterization class.
*
* @author Erich Schubert
*
* @apiviz.exclude
*/
public static class Parameterizer extends AbstractParameterizer {
int externalIdIndex = -1;
@Override
protected void makeOptions(Parameterization config) {
super.makeOptions(config);
final IntParameter externalIdIndexParam = new IntParameter(EXTERNALID_INDEX_ID, new GreaterEqualConstraint(0));
if(config.grab(externalIdIndexParam)) {
externalIdIndex = externalIdIndexParam.getValue();
}
}
@Override
protected Object makeInstance() {
return new ExternalIDFilter(externalIdIndex);
}
}
}