opennlp.tools.ml.model.DataIndexer Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package opennlp.tools.ml.model;
import java.io.IOException;
import java.util.Map;
import opennlp.tools.util.ObjectStream;
import opennlp.tools.util.TrainingParameters;
/**
* Represents an indexer which compresses events in memory and performs feature selection.
*
* @see ObjectStream
* @see TrainingParameters
*/
public interface DataIndexer {
/**
* @return Retrieves a 2-dimensional array whose first dimension is the event
* index and array this refers to contains the contexts for that event.
*/
int[][] getContexts();
/**
* @return Retrieves an array indexed by the event index indicating
* the number of times a particular event was seen.
*/
int[] getNumTimesEventsSeen();
/**
* @return Retrieves an array indicating the outcome index for each event.
*/
int[] getOutcomeList();
/**
* @return Retrieves an array of predicate/context names indexed by context index.
* These indices are the value of the array returned by {@link #getContexts()}.
*/
String[] getPredLabels();
/**
* @return Retrieves an array of the count of each predicate in the events.
*/
int[] getPredCounts();
/**
* @return Retrieves an array of outcome names indexed by outcome index.
*/
String[] getOutcomeLabels();
/**
* @return Retrieves the values associated with each event context or
* {@code null} if integer values are to be used.
*/
float[][] getValues();
/**
* @return Retrieves the number of total events indexed.
*/
int getNumEvents();
/**
* Sets parameters used during the data indexing.
*
* @param trainParams The {@link TrainingParameters} to be used.
* @param reportMap The {@link Map} used for reporting.
*/
void init(TrainingParameters trainParams, Map reportMap);
/**
* Performs the data indexing.
*
* Note:
* Make sure the {@link #init(TrainingParameters, Map)} method is called first.
*
* @param eventStream A {@link ObjectStream} of events used as input.
*
* @throws IOException Thrown if IO errors occurred during indexing.
*/
void index(ObjectStream eventStream) throws IOException;
}