package de.lmu.ifi.dbs.elki.datasource.filter.selection;
/*
This file is part of ELKI:
Environment for Developing KDD-Applications Supported by Index-Structures
Copyright (C) 2015
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 .
*/
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import de.lmu.ifi.dbs.elki.data.LabelList;
import de.lmu.ifi.dbs.elki.datasource.bundle.BundleMeta;
import de.lmu.ifi.dbs.elki.datasource.filter.AbstractStreamFilter;
import de.lmu.ifi.dbs.elki.datasource.filter.FilterUtil;
import de.lmu.ifi.dbs.elki.logging.Logging;
import de.lmu.ifi.dbs.elki.utilities.Alias;
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.parameterization.Parameterization;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.Flag;
import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.PatternParameter;
/**
* A filter to select data set by their label.
*
* @author Erich Schubert
* @since 0.4.0
*
* @apiviz.uses LabelList oneway - - «reads»
*/
@Alias({ "de.lmu.ifi.dbs.elki.datasource.filter.ByLabelFilter", //
"de.lmu.ifi.dbs.elki.datasource.filter.FilterByLabelFilter" })
public class ByLabelFilter extends AbstractStreamFilter {
/**
* Class logger
*/
private static final Logging LOG = Logging.getLogger(ByLabelFilter.class);
/**
* The filter pattern matcher
*/
private final Matcher matcher;
/**
* Inversion flag
*/
private final boolean inverted;
/**
* Label column
*/
private int lblcol = -1;
/**
* Constructor.
*
* @param pattern Filter pattern
* @param inverted Inversion flag
*/
public ByLabelFilter(Pattern pattern, boolean inverted) {
super();
this.matcher = pattern.matcher("");
this.inverted = inverted;
}
@Override
public BundleMeta getMeta() {
return source.getMeta();
}
@Override
public Object data(int rnum) {
return source.data(rnum);
}
@Override
public Event nextEvent() {
while(true) {
Event ev = source.nextEvent();
switch(ev){
case END_OF_STREAM:
if(lblcol < 0) {
LOG.warning("By label filter was used, but never saw a label relation!");
}
return Event.END_OF_STREAM;
case META_CHANGED:
// Search for the first label column
if(lblcol < 0) {
BundleMeta meta = source.getMeta();
lblcol = FilterUtil.findLabelColumn(meta);
}
return Event.META_CHANGED;
case NEXT_OBJECT:
if(lblcol > 0) {
Object l = source.data(lblcol);
if(l instanceof LabelList) {
boolean good = false;
final LabelList ll = (LabelList) l;
for(int i = 0; i < ll.size(); i++) {
matcher.reset(ll.get(i));
if(matcher.matches()) {
good = true;
break;
}
}
if(good == inverted) {
continue;
}
}
else {
matcher.reset(l.toString());
if(!matcher.matches()) {
continue;
}
}
}
else {
// No labels known yet.
if(!inverted) {
continue;
}
}
return Event.NEXT_OBJECT;
default:
LOG.warning("Unknown event: " + ev);
}
}
}
/**
* Parameterization class.
*
* @author Erich Schubert
*
* @apiviz.exclude
*/
public static class Parameterizer extends AbstractParameterizer {
/**
* Parameter that specifies the filter pattern (regular expression).
*
* Key: {@code -patternfilter.pattern}
*
*/
public static final OptionID LABELFILTER_PATTERN_ID = new OptionID("patternfilter.pattern", "The filter pattern to use.");
/**
* Flag to use the pattern in inverted mode
*
* Key: {@code -patternfilter.invert}
*
*/
public static final OptionID LABELFILTER_PATTERN_INVERT_ID = new OptionID("patternfilter.invert", "Flag to invert pattern.");
/**
* The pattern configured.
*/
Pattern pattern = null;
/**
* Inversion flag
*/
private boolean inverted = false;
@Override
protected void makeOptions(Parameterization config) {
super.makeOptions(config);
final PatternParameter patternP = new PatternParameter(LABELFILTER_PATTERN_ID);
if(config.grab(patternP)) {
pattern = patternP.getValue();
}
final Flag invertedF = new Flag(LABELFILTER_PATTERN_INVERT_ID);
if(config.grab(invertedF)) {
inverted = invertedF.getValue().booleanValue();
}
}
@Override
protected ByLabelFilter makeInstance() {
return new ByLabelFilter(pattern, inverted);
}
}
}