opennlp.tools.ml.naivebayes.Probability Maven / Gradle / Ivy
/*
* 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.naivebayes;
/**
* Class implementing the probability for a label.
*
* @param the label (category) class
*
*/
public class Probability {
protected T label;
protected double probability = 1.0;
public Probability(T label) {
this.label = label;
}
/**
* Assigns a probability to a label, discarding any previously assigned probability.
*
* @param probability the probability to assign
*/
public void set(double probability) {
this.probability = probability;
}
/**
* Assigns a probability to a label, discarding any previously assigned probability.
*
* @param probability the probability to assign
*/
public void set(Probability probability) {
this.probability = probability.get();
}
/**
* Assigns a probability to a label, discarding any previously assigned probability,
* if the new probability is greater than the old one.
*
* @param probability the probability to assign
*/
public void setIfLarger(double probability) {
if (this.probability < probability) {
this.probability = probability;
}
}
/**
* Assigns a probability to a label, discarding any previously assigned probability,
* if the new probability is greater than the old one.
*
* @param probability the probability to assign
*/
public void setIfLarger(Probability probability) {
if (this.probability < probability.get()) {
this.probability = probability.get();
}
}
/**
* Checks if a probability is greater than the old one.
*
* @param probability the probability to assign
*/
public boolean isLarger(Probability probability) {
return this.probability < probability.get();
}
/**
* Assigns a log probability to a label, discarding any previously assigned probability.
*
* @param probability the log probability to assign
*/
public void setLog(double probability) {
set(Math.exp(probability));
}
/**
* Compounds the existing probability mass on the label with the new probability passed in to the method.
*
* @param probability the probability weight to add
*/
public void addIn(double probability) {
set(this.probability * probability);
}
/**
* Returns the probability associated with a label
*
* @return the probability associated with the label
*/
public Double get() {
return probability;
}
/**
* Returns the log probability associated with a label
*
* @return the log probability associated with the label
*/
public Double getLog() {
return Math.log(get());
}
/**
* Returns the probabilities associated with all labels
*
* @return the HashMap of labels and their probabilities
*/
public T getLabel() {
return label;
}
public String toString() {
return label == null ? "" + probability : label.toString() + ":" + probability;
}
}