/*
* RapidMiner
*
* Copyright (C) 2001-2008 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.features.construction;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import com.rapidminer.example.Attribute;
import com.rapidminer.example.AttributeParser;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.operator.IOObject;
import com.rapidminer.operator.Operator;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.UserError;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeBoolean;
import com.rapidminer.parameter.ParameterTypeFile;
import com.rapidminer.parameter.ParameterTypeList;
import com.rapidminer.parameter.ParameterTypeString;
/**
* <p>This operator generates new user specified features. The new features are
* specified by their function names (prefix notation) and their arguments using
* the names of existing features.<br/> Legal function names include +, -, etc. and
* the functions
* norm, sin, cos, tan, atan, exp, log, min, max, floor, ceil, round, sqrt, abs,
* and pow. Constant values can be defined by "const[value]()" where
* value is the desired value. Do not forget the empty round brackets. Example:
* <code>+(a1, -(a2, a3))</code> will calculate the sum of the attribute
* <code>a1</code> and the difference of the attributes <code>a2</code> and
* <code>a3</code>. <br/> Features are generated in the following order:</p>
* <ol>
* <li>Features specified by the file referenced by the parameter "filename"
* are generated</li>
* <li>Features specified by the parameter list "functions" are generated</li>
* <li>If "keep_all" is false, all of the old attributes are removed now</li>
* </ol>
*
* <p>
* The list of supported functions include +, -, etc. and the functions
* sin, cos, tan, atan, exp, log, min, max, floor, ceil, round, sqrt, abs, sgn, pow.
* </p>
*
* @see com.rapidminer.generator.FeatureGenerator
* @author Simon Fischer, Ingo Mierswa
* @version $Id: FeatureGenerationOperator.java,v 1.9 2008/07/13 23:25:24 ingomierswa Exp $
*/
public class FeatureGenerationOperator extends Operator {
/** The parameter name for "Create the attributes listed in this file (written by an AttributeConstructionsWriter)." */
public static final String PARAMETER_FILENAME = "filename";
/** The parameter name for "List of functions to generate." */
public static final String PARAMETER_FUNCTIONS = "functions";
/** The parameter name for "If set to true, all the original attributes are kept, otherwise they are removed from the example set." */
public static final String PARAMETER_KEEP_ALL = "keep_all";
private static final Class[] INPUT_CLASSES = { ExampleSet.class };
private static final Class[] OUTPUT_CLASSES = { ExampleSet.class };
public FeatureGenerationOperator(OperatorDescription description) {
super(description);
}
public Class<?>[] getInputClasses() {
return INPUT_CLASSES;
}
public Class<?>[] getOutputClasses() {
return OUTPUT_CLASSES;
}
public IOObject[] apply() throws OperatorException {
ExampleSet exampleSet = getInput(ExampleSet.class);
boolean keepAll = getParameterAsBoolean(PARAMETER_KEEP_ALL);
List<Attribute> oldAttributes = new LinkedList<Attribute>();
for (Attribute attribute : exampleSet.getAttributes()) {
oldAttributes.add(attribute);
}
AttributeParser parser = new AttributeParser(exampleSet.getExampleTable());
File file = getParameterAsFile(PARAMETER_FILENAME);
if (file != null) {
InputStream in = null;
try {
in = new FileInputStream(file);
parser.generateAll(this, exampleSet, in);
} catch (IOException e) {
throw new UserError(this, e, 302, new Object[] { file, e.getMessage() });
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
logError("Cannot close stream to file " + file);
}
}
}
}
Iterator j = getParameterList(PARAMETER_FUNCTIONS).iterator();
while (j.hasNext()) {
Object[] nameFunctionPair = (Object[]) j.next();
Attribute attribute = parser.generateAttribute(this, (String) nameFunctionPair[1]);
if (attribute != null) {
attribute.setName((String) nameFunctionPair[0]);
exampleSet.getAttributes().addRegular(attribute);
} else {
logWarning("Cannot generate attribute: " + nameFunctionPair[0] + " --> " + nameFunctionPair[1]);
}
checkForStop();
}
if (!keepAll) {
for (Attribute oldAttribute : oldAttributes) {
exampleSet.getAttributes().remove(oldAttribute);
}
}
return new IOObject[] { exampleSet };
}
public List<ParameterType> getParameterTypes() {
List<ParameterType> types = super.getParameterTypes();
ParameterType type = new ParameterTypeFile(PARAMETER_FILENAME, "Create the attributes listed in this file (written by an AttributeConstructionsWriter).", "att", true);
type.setExpert(false);
types.add(type);
type = new ParameterTypeList(PARAMETER_FUNCTIONS, "List of functions to generate.", new ParameterTypeString("function", "Function and arguments to use for generation."));
type.setExpert(false);
types.add(type);
types.add(new ParameterTypeBoolean(PARAMETER_KEEP_ALL, "If set to true, all the original attributes are kept, otherwise they are removed from the example set.", false));
return types;
}
}