opennlp.tools.ml.model.MaxentModel 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package opennlp.tools.ml.model;
/**
* Interface for maximum entropy models.
**/
public interface MaxentModel {
/**
* Evaluates a context.
*
* @param context A list of String names of the contextual predicates
* which are to be evaluated together.
* @return an array of the probabilities for each of the different
* outcomes, all of which sum to 1.
*
**/
double[] eval(String[] context);
/**
* Evaluates a context.
*
* @param context A list of String names of the contextual predicates
* which are to be evaluated together.
* @param probs An array which is populated with the probabilities for each of the different
* outcomes, all of which sum to 1.
* @return an array of the probabilities for each of the different outcomes, all of which sum to 1.
**/
double[] eval(String[] context, double[] probs);
/**
* Evaluates a contexts with the specified context values.
* @param context A list of String names of the contextual predicates
* which are to be evaluated together.
* @param values The values associated with each context.
* @return an array of the probabilities for each of the different outcomes, all of which sum to 1.
*/
double[] eval(String[] context, float[] values);
/**
* Simple function to return the outcome associated with the index
* containing the highest probability in the double[].
*
* @param outcomes A double[] as returned by the
* eval(String[] context)
* method.
* @return the String name of the best outcome
**/
String getBestOutcome(double[] outcomes);
/**
* Return a string matching all the outcome names with all the
* probabilities produced by the eval(String[]
* context) method.
*
* @param outcomes A double[] as returned by the
* eval(String[] context)
* method.
* @return String containing outcome names paired with the normalized
* probability (contained in the double[] ocs)
* for each one.
**/
// TODO: This should be removed, can't be used anyway without format spec
String getAllOutcomes(double[] outcomes);
/**
* Gets the String name of the outcome associated with the index
* i.
*
* @param i the index for which the name of the associated outcome is
* desired.
* @return the String name of the outcome
**/
String getOutcome(int i);
/**
* Gets the index associated with the String name of the given
* outcome.
*
* @param outcome the String name of the outcome for which the
* index is desired
* @return the index if the given outcome label exists for this
* model, -1 if it does not.
**/
int getIndex(String outcome);
/*
* Returns the data structures relevant to storing the model.
**/
// public Object[] getDataStructures();
/** Returns the number of outcomes for this model.
* @return The number of outcomes.
**/
int getNumOutcomes();
}