/*
* 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.meta;
import java.util.Iterator;
import java.util.List;
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.ParameterTypeList;
import com.rapidminer.parameter.ParameterTypeString;
/**
* Sets a list of parameters using existing parameter values. <br/>
*
* The operator is similar to {@link ParameterSetter}, but differs from that in
* not requiring a ParameterSet input. It simply reads a parameter value from a
* source and uses it to set the parameter value of a target parameter. Both,
* source and target, are given in the format 'operator'.'parameter'. <br/>
*
* This operator is more general than ParameterSetter and could completely
* replace it. It is most useful, if you need a parameter which is optimized
* more than once within the optimization loop - ParameterSetter cannot be used
* here. <br/>
*
* These parameters can either be generated by a
* {@link ParameterOptimizationOperator} or read by a
* {@link com.rapidminer.operator.io.ParameterSetLoader}. This operator is
* useful, e.g. in the following scenario. If one wants to find the best
* parameters for a certain learning scheme, one usually is also interested in
* the model generated with this parameters. While the first is easily possible
* using a {@link ParameterOptimizationOperator}, the latter is not possible
* because the {@link ParameterOptimizationOperator} does not return the
* IOObjects produced within, but only a parameter set. This is, because the
* parameter optimization operator knows nothing about models, but only about
* the performance vectors produced within. Producing performance vectors does
* not necessarily require a model. <br/> To solve this problem, one can use a
* <code>ParameterSetter</code>. Usually, a process definition with a
* <code>ParameterSetter</code> contains at least two operators of the same
* type, typically a learner. One learner may be an inner operator of the
* {@link ParameterOptimizationOperator} and may be named "Learner",
* whereas a second learner of the same type named "OptimalLearner"
* follows the parameter optimization and should use the optimal parameter set
* found by the optimization. In order to make the <code>ParameterSetter</code>
* set the optimal parameters of the right operator, one must specify its name.
* Therefore, the parameter list <var>name_map</var> was introduced. Each
* parameter in this list maps the name of an operator that was used during
* optimization (in our case this is "Learner") to an operator that
* should now use these parameters (in our case this is
* "OptimalLearner").
*
* @author Robert Rudolph
* @version $Id: ParameterCloner.java,v 1.6 2008/07/07 07:06:39 ingomierswa Exp $
*/
public class ParameterCloner extends Operator {
/** The parameter name for "A list mapping operator parameters from the set to other operator parameters in the process setup." */
public static final String PARAMETER_NAME_MAP = "name_map";
private static final Class[] INPUT_CLASSES = new Class[0];
private static final Class[] OUTPUT_CLASSES = new Class[0];
public ParameterCloner(OperatorDescription description) {
super(description);
}
public IOObject[] apply() throws OperatorException {
List nameList = getParameterList(PARAMETER_NAME_MAP);
Iterator i = nameList.iterator();
while (i.hasNext()) {
Object[] keyValue = (Object[]) i.next();
String[] source = ((String) keyValue[0]).split("\\.");
String[] target = ((String) keyValue[1]).split("\\.");
if (source.length != 2)
throw new UserError(this, 907, keyValue[0]);
if (target.length != 2)
throw new UserError(this, 907, keyValue[1]);
Operator operator = getProcess().getOperator(source[0]);
Object value = operator.getParameter(source[1]);
operator = getProcess().getOperator(target[0]);
operator.getParameters().setParameter(target[1], value.toString());
}
return new IOObject[0];
}
public Class<?>[] getInputClasses() {
return INPUT_CLASSES;
}
public Class<?>[] getOutputClasses() {
return OUTPUT_CLASSES;
}
public List<ParameterType> getParameterTypes() {
List<ParameterType> types = super.getParameterTypes();
types.add(new ParameterTypeList(PARAMETER_NAME_MAP, "A list mapping operator parameters from the set to other operator parameters in the process setup.", new ParameterTypeString("operator_parameters",
"Key and value are 'operator'.'parameter'. The key species the source parameter, the value the destination.")));
return types;
}
}