org.jpmml.evaluator.HasGroupFields Maven / Gradle / Ivy

/*
 * Copyright (c) 2016 Villu Ruusmann
 *
 * This file is part of JPMML-Evaluator
 *
 * JPMML-Evaluator 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.
 *
 * JPMML-Evaluator 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 JPMML-Evaluator.  If not, see .
 */
package org.jpmml.evaluator;

import java.util.List;

import org.dmg.pmml.MiningFunction;
import org.dmg.pmml.MiningSchema;
import org.dmg.pmml.Model;

/**
 * 
 * A marker interface for models that expect the application to group
 * many scalar-valued data records to a single collection-valued data record.
 * The grouping is applied to {@link #getActiveFields() active field} values.
 * 
 *
 * Aggregating data records:
 * {@code
 * Evaluator evaluator = ...;
 * List> preparedRecords = ...;
 * if(evaluator instanceof HasGroupFields){
 *   HasGroupFields hasGroupFields = (HasGroupFields)evaluator;
 *   preparedRecords = EvaluatorUtil.groupRows(hasGroupFields, preparedRecords);
 * }
 * }
 *
 * @see EvaluatorUtil#groupRows(HasGroupFields, List)
 */
public interface HasGroupFields extends HasActiveFields {

	/**
	 * 
	 * Gets the group fields of a {@link Model} from its {@link MiningSchema}.
	 * 
	 *
	 * 
	 * This field set is relevant for {@link MiningFunction#ASSOCIATION_RULES association rules} model type only.
	 * 
	 */
	List getGroupFields();
}