    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     */
    017    package org.apache.commons.math.stat.descriptive;
    018
    019
    020    /**
    021     * Base interface implemented by all statistics.
    022     *
    023     * @version $Revision: 811685 $ $Date: 2009-09-05 19:36:48 +0200 (sam. 05 sept. 2009) $
    024     */
    025    public interface UnivariateStatistic {
    026
    027        /**
    028         * Returns the result of evaluating the statistic over the input array.
    029         *
    030         * @param values input array
    031         * @return the value of the statistic applied to the input array
    032         */
    033        double evaluate(double[] values);
    034
    035        /**
    036         * Returns the result of evaluating the statistic over the specified entries
    037         * in the input array.
    038         *
    039         * @param values the input array
    040         * @param begin the index of the first element to include
    041         * @param length the number of elements to include
    042         * @return the value of the statistic applied to the included array entries
    043         */
    044        double evaluate(double[] values, int begin, int length);
    045
    046        /**
    047         * Returns a copy of the statistic with the same internal state.
    048         *
    049         * @return a copy of the statistic
    050         */
    051        UnivariateStatistic copy();
    052
    053    }