/*
* RapidMiner
*
* Copyright (C) 2001-2011 by Rapid-I and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapid-i.com
*
* 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/.
*/
package com.rapidminer.operator.preprocessing.filter;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map.Entry;
import java.util.Set;
import java.util.TreeSet;
import com.rapidminer.example.Attribute;
import com.rapidminer.example.Example;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.example.table.AttributeFactory;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.annotation.ResourceConsumptionEstimator;
import com.rapidminer.operator.ports.metadata.AttributeMetaData;
import com.rapidminer.operator.ports.metadata.ExampleSetMetaData;
import com.rapidminer.operator.ports.metadata.SetRelation;
import com.rapidminer.operator.preprocessing.AbstractValueProcessing;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeInt;
import com.rapidminer.parameter.UndefinedParameterError;
import com.rapidminer.tools.Ontology;
import com.rapidminer.tools.OperatorResourceConsumptionHandler;
/**
* This operator creates new attributes from nominal attributes where the new attributes contain only
* substrings of the original values. Please note that the counting starts with 1 and that the first
* and the last character will be included in the resulting substring. For example, the value is
* "RapidMiner" and the first index is set to 6 and the last index is set to 9 the result will be
* "Mine". If the last index is larger than the length of the word, the resulting substrings
* will end with the last character.
*
* @author Ingo Mierswa, Tobias Malbrecht
*/
public class AttributeValueSubstring extends AbstractValueProcessing {
public static final String PARAMETER_FIRST = "first_character_index";
public static final String PARAMETER_LAST = "last_character_index";
public AttributeValueSubstring(OperatorDescription description) {
super(description);
}
@Override
public ExampleSet applyOnFiltered(ExampleSet exampleSet) throws OperatorException {
int firstIndex = getParameterAsInt(PARAMETER_FIRST);
int lastIndex = getParameterAsInt(PARAMETER_LAST);
LinkedHashMap<Attribute, Attribute> attributeMap = new LinkedHashMap<Attribute, Attribute>();
for (Attribute oldAttribute : exampleSet.getAttributes()) {
Attribute newAttribute = AttributeFactory.createAttribute(oldAttribute.getValueType());
attributeMap.put(oldAttribute, newAttribute);
for (String value : oldAttribute.getMapping().getValues()) {
int actualFirst = firstIndex - 1;
int actualLast = lastIndex <= value.length() ? lastIndex : value.length();
String substringValue = value.substring(actualFirst, actualLast);
if (substringValue.length() > 0) {
newAttribute.getMapping().mapString(substringValue);
}
}
}
for (Entry<Attribute, Attribute> entry : attributeMap.entrySet()) {
Attribute oldAttribute = entry.getKey();
Attribute newAttribute = entry.getValue();
exampleSet.getExampleTable().addAttribute(newAttribute);
exampleSet.getAttributes().addRegular(newAttribute);
for (Example example : exampleSet) {
double value = example.getValue(oldAttribute);
if (Double.isNaN(value)) {
example.setValue(newAttribute, Double.NaN);
} else {
String stringValue = oldAttribute.getMapping().mapIndex((int) value);
int actualFirst = firstIndex - 1;
int actualLast = lastIndex <= stringValue.length() ? lastIndex : stringValue.length();
if (lastIndex < firstIndex) {
example.setValue(newAttribute, Double.NaN);
} else {
String substringValue = stringValue.substring(actualFirst, actualLast);
if (substringValue.length() == 0) {
example.setValue(newAttribute, Double.NaN);
} else {
example.setValue(newAttribute, substringValue);
}
}
}
}
exampleSet.getAttributes().remove(oldAttribute);
newAttribute.setName(oldAttribute.getName());
}
return exampleSet;
}
@Override
public ExampleSetMetaData applyOnFilteredMetaData(ExampleSetMetaData emd) throws UndefinedParameterError {
int firstIndex = getParameterAsInt(PARAMETER_FIRST);
int lastIndex = getParameterAsInt(PARAMETER_LAST);
for (AttributeMetaData amd : emd.getAllAttributes()) {
Set<String> valueSet = new TreeSet<String>();
for (String value : amd.getValueSet()) {
int actualFirst = firstIndex - 1;
int actualLast = lastIndex <= value.length() ? lastIndex : value.length();
String substringValue = value.substring(actualFirst, actualLast);
if (substringValue.length() > 0) {
valueSet.add(substringValue);
}
}
amd.setValueSet(valueSet, SetRelation.SUBSET);
}
return emd;
}
@Override
protected int[] getFilterValueTypes() {
return new int[] { Ontology.NOMINAL };
}
@Override
public List<ParameterType> getParameterTypes() {
List<ParameterType> types = super.getParameterTypes();
ParameterType type = new ParameterTypeInt(PARAMETER_FIRST, "The index of the first character of the substring which should be kept (counting starts with 1, 0: start with beginning of value).", 1, Integer.MAX_VALUE, 1);
type.setExpert(false);
types.add(type);
type = new ParameterTypeInt(PARAMETER_LAST, "The index of the last character of the substring which should be kept (counting starts with 1, 0: end with end of value).", 1, Integer.MAX_VALUE, Integer.MAX_VALUE);
type.setExpert(false);
types.add(type);
return types;
}
@Override
public boolean writesIntoExistingData() {
return false;
}
@Override
public ResourceConsumptionEstimator getResourceConsumptionEstimator() {
return OperatorResourceConsumptionHandler.getResourceConsumptionEstimator(getInputPort(), AttributeValueSubstring.class, null);
}
}