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Creating an Operator Class

Time to create a new class for your operator. Each normal operator has to extend Operator or a subclass of Operator. There are many subclasses for more specialized operators (e.g., learning operators), but this example uses the simplest case. Frequently used subclasses of Operator are AbstractLearner, AbstractReader and AbstractWriter. If you are interested in more, take a look at the type hierarchy of Operator.

  1. Create a new package for your operator class. It should have the name groupId.operator.
  2. Create a new Java class with a meaningful name. The class has to extend Operator from the RapidMiner core. You have to override the constructor.

That's it. Your operator class should look like this:

But wait! You want the operator to do something. Therefore, override the method doWork(). The default implementation simply does nothing. In this example, the operator will write logs to the Log panel.

package com.rapidminer.extension.operator;

import java.util.logging.Level;
import com.rapidminer.operator.Operator;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;

 * Describe what your operator does.
 * @author Insert your name here
public class MyOwnOperator extends Operator {

     * @param description
    public MyOwnOperator(OperatorDescription description) {

    public void doWork() throws OperatorException {
        LogService.getRoot().log(Level.INFO, "Doing something...");


Once you have implemented an operator, you'll want to test it in RapidMiner. Unfortunately, RapidMiner isn't prophetic. (Actually it could be, but using data mining methods for guessing class usage would be overkill.) Instead, you must specify class use.