1 /* 2 * Copyright 2004 The Apache Software Foundation. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package org.apache.commons.math.stat.descriptive; 17 18 /** 19 * Reporting interface for basic univariate statistics. 20 * 21 * @version $Revision: 155427 $ $Date: 2005-02-26 06:11:52 -0700 (Sat, 26 Feb 2005) $ 22 */ 23 public interface StatisticalSummary { 24 /** 25 * Returns the <a href="http://www.xycoon.com/arithmetic_mean.htm"> 26 * arithmetic mean </a> of the available values 27 * @return The mean or Double.NaN if no values have been added. 28 */ 29 public abstract double getMean(); 30 /** 31 * Returns the variance of the available values. 32 * @return The variance, Double.NaN if no values have been added 33 * or 0.0 for a single value set. 34 */ 35 public abstract double getVariance(); 36 /** 37 * Returns the standard deviation of the available values. 38 * @return The standard deviation, Double.NaN if no values have been added 39 * or 0.0 for a single value set. 40 */ 41 public abstract double getStandardDeviation(); 42 /** 43 * Returns the maximum of the available values 44 * @return The max or Double.NaN if no values have been added. 45 */ 46 public abstract double getMax(); 47 /** 48 * Returns the minimum of the available values 49 * @return The min or Double.NaN if no values have been added. 50 */ 51 public abstract double getMin(); 52 /** 53 * Returns the number of available values 54 * @return The number of available values 55 */ 56 public abstract long getN(); 57 /** 58 * Returns the sum of the values that have been added to Univariate. 59 * @return The sum or Double.NaN if no values have been added 60 */ 61 public abstract double getSum(); 62 }