001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.math3.stat.descriptive;
018
019/**
020 *  Reporting interface for basic univariate statistics.
021 *
022  * @version $Id: StatisticalSummary.java 1416643 2012-12-03 19:37:14Z tn $
023 */
024public interface StatisticalSummary {
025
026    /**
027     * Returns the <a href="http://www.xycoon.com/arithmetic_mean.htm">
028     * arithmetic mean </a> of the available values
029     * @return The mean or Double.NaN if no values have been added.
030     */
031    double getMean();
032    /**
033     * Returns the variance of the available values.
034     * @return The variance, Double.NaN if no values have been added
035     * or 0.0 for a single value set.
036     */
037    double getVariance();
038    /**
039     * Returns the standard deviation of the available values.
040     * @return The standard deviation, Double.NaN if no values have been added
041     * or 0.0 for a single value set.
042     */
043    double getStandardDeviation();
044    /**
045     * Returns the maximum of the available values
046     * @return The max or Double.NaN if no values have been added.
047     */
048    double getMax();
049    /**
050    * Returns the minimum of the available values
051    * @return The min or Double.NaN if no values have been added.
052    */
053    double getMin();
054    /**
055     * Returns the number of available values
056     * @return The number of available values
057     */
058    long getN();
059    /**
060     * Returns the sum of the values that have been added to Univariate.
061     * @return The sum or Double.NaN if no values have been added
062     */
063    double getSum();
064
065}