/*
* 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.meta;
import java.util.List;
import com.rapidminer.example.Attribute;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.operator.OperatorChain;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.ValueDouble;
import com.rapidminer.operator.ValueString;
import com.rapidminer.operator.ports.InputPort;
import com.rapidminer.operator.ports.OutputPort;
import com.rapidminer.operator.ports.metadata.ExampleSetMetaData;
import com.rapidminer.operator.ports.metadata.MetaData;
import com.rapidminer.operator.ports.metadata.PassThroughRule;
import com.rapidminer.operator.ports.metadata.SimplePrecondition;
import com.rapidminer.operator.ports.metadata.SubprocessTransformRule;
import com.rapidminer.operator.tools.AttributeSubsetSelector;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeString;
/**
* <p>This operator takes an input data set and applies its inner operators
* as often as the number of features of the input data is. Inner operators
* can access the current feature name by a macro, whose name can be
* specified via the parameter <code>iteration_macro</code>.</p>
*
* <p>The user can specify with a parameter if this loop should iterate over
* all features or only over features with a specific value type, i.e. only
* over numerical or over nominal features. A regular expression can also be
* specified which is used as a filter, i.e. the inner operators are only
* applied for feature names matching the filter expression.</p>
*
* @author Ingo Mierswa, Tobias Malbrecht
*/
public class FeatureIterator extends OperatorChain {
private final InputPort exampleSetInput = getInputPorts().createPort("example set", ExampleSet.class);
private final OutputPort exampleSetOutput = getOutputPorts().createPort("example set");
private final OutputPort exampleSetInnerSource = getSubprocess(0).getInnerSources().createPort("example set");
private final InputPort exampleSetInnerSink = getSubprocess(0).getInnerSinks().createPort("example set");
public static final String PARAMETER_ITERATION_MACRO = "iteration_macro";
public static final String DEFAULT_ITERATION_MACRO_NAME = "loop_attribute";
private int iteration;
private String currentName = null;
private final AttributeSubsetSelector attributeSelector = new AttributeSubsetSelector(this, exampleSetInput);
public FeatureIterator(OperatorDescription description) {
super(description, "Subprocess");
exampleSetInnerSink.addPrecondition(new SimplePrecondition(exampleSetInnerSink, new ExampleSetMetaData(), false));
getTransformer().addRule(new PassThroughRule(exampleSetInput, exampleSetInnerSource, false));
getTransformer().addRule(new SubprocessTransformRule(getSubprocess(0)));
getTransformer().addRule(new PassThroughRule(exampleSetInput, exampleSetOutput, false) {
@Override
public MetaData modifyMetaData(MetaData unmodifiedMetaData) {
if (exampleSetInnerSink.isConnected()) {
return exampleSetInnerSink.getMetaData();
} else {
// due to side effects, we cannot make any guarantee about the output.
return new ExampleSetMetaData();
}
}
});
addValue(new ValueDouble("iteration", "The number of the current iteration / loop.") {
@Override
public double getDoubleValue() {
return iteration;
}
});
addValue(new ValueString("feature_name", "The number of the current feature.") {
@Override
public String getStringValue() {
return currentName;
}
});
}
@Override
public void doWork() throws OperatorException {
ExampleSet exampleSet = exampleSetInput.getData();
String iterationMacroName = getParameterAsString(PARAMETER_ITERATION_MACRO);
// filter and loop
iteration = 0;
for (Attribute attribute : attributeSelector.getAttributeSubset(exampleSet, false)) {
String name = attribute.getName();
getProcess().getMacroHandler().addMacro(iterationMacroName, name);
currentName = name;
applyInnerOperators(exampleSet);
checkForStop();
iteration++;
}
getProcess().getMacroHandler().removeMacro(iterationMacroName);
if (exampleSetInnerSink.isConnected()) {
exampleSetOutput.deliver(exampleSetInnerSink.getData());
} else {
exampleSetOutput.deliver(exampleSet);
}
}
private void applyInnerOperators(ExampleSet inputExampleSet) throws OperatorException {
ExampleSet iterationSet;
// if inner sink is connected, use its data as an input to iteration 2...n
// otherwise, always feed a clone into the subprocess.
if(exampleSetInnerSink.isConnected()) {
if (iteration == 0) {
iterationSet = inputExampleSet;
} else {
iterationSet = exampleSetInnerSink.getData();
}
} else {
iterationSet = (ExampleSet)inputExampleSet.clone();
}
exampleSetInnerSource.deliver(iterationSet);
getSubprocess(0).execute();
}
@Override
public boolean shouldAutoConnect(InputPort inputPort) {
if (inputPort == exampleSetInnerSink) {
return true;
} else {
return super.shouldAutoConnect(inputPort);
}
}
@Override
public List<ParameterType> getParameterTypes() {
List<ParameterType> types = super.getParameterTypes();
types.addAll(attributeSelector.getParameterTypes());
types.add(new ParameterTypeString(PARAMETER_ITERATION_MACRO, "The name of the macro which holds the name of the current feature in each iteration.", DEFAULT_ITERATION_MACRO_NAME, false));
return types;
}
}