/*
* 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 org.apache.commons.math3.stat.descriptive;
import org.apache.commons.math3.exception.MathIllegalArgumentException;
/**
* Extends the definition of {@link UnivariateStatistic} with
* {@link #increment} and {@link #incrementAll(double[])} methods for adding
* values and updating internal state.
* <p>
* This interface is designed to be used for calculating statistics that can be
* computed in one pass through the data without storing the full array of
* sample values.</p>
*
*/
public interface StorelessUnivariateStatistic extends UnivariateStatistic {
/**
* Updates the internal state of the statistic to reflect the addition of the new value.
* @param d the new value.
*/
void increment(double d);
/**
* Updates the internal state of the statistic to reflect addition of
* all values in the values array. Does not clear the statistic first --
* i.e., the values are added <strong>incrementally</strong> to the dataset.
*
* @param values array holding the new values to add
* @throws MathIllegalArgumentException if the array is null
*/
void incrementAll(double[] values) throws MathIllegalArgumentException;
/**
* Updates the internal state of the statistic to reflect addition of
* the values in the designated portion of the values array. Does not
* clear the statistic first -- i.e., the values are added
* <strong>incrementally</strong> to the dataset.
*
* @param values array holding the new values to add
* @param start the array index of the first value to add
* @param length the number of elements to add
* @throws MathIllegalArgumentException if the array is null or the index
*/
void incrementAll(double[] values, int start, int length) throws MathIllegalArgumentException;
/**
* Returns the current value of the Statistic.
* @return value of the statistic, <code>Double.NaN</code> if it
* has been cleared or just instantiated.
*/
double getResult();
/**
* Returns the number of values that have been added.
* @return the number of values.
*/
long getN();
/**
* Clears the internal state of the Statistic
*/
void clear();
/**
* Returns a copy of the statistic with the same internal state.
*
* @return a copy of the statistic
*/
StorelessUnivariateStatistic copy();
}