    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.analysis.integration;
    018
    019    import org.apache.commons.math.ConvergenceException;
    020    import org.apache.commons.math.ConvergingAlgorithm;
    021    import org.apache.commons.math.FunctionEvaluationException;
    022    import org.apache.commons.math.analysis.UnivariateRealFunction;
    023
    024    /**
    025     * Interface for univariate real integration algorithms.
    026     *
    027     * @version $Revision: 1070725 $ $Date: 2011-02-15 02:31:12 +0100 (mar. 15 f??vr. 2011) $
    028     * @since 1.2
    029     */
    030    public interface UnivariateRealIntegrator extends ConvergingAlgorithm {
    031
    032       /**
    033         * Set the lower limit for the number of iterations.
    034         * <p>
    035         * Minimal iteration is needed to avoid false early convergence, e.g.
    036         * the sample points happen to be zeroes of the function. Users can
    037         * use the default value or choose one that they see as appropriate.</p>
    038         * <p>
    039         * A <code>ConvergenceException</code> will be thrown if this number
    040         * is not met.</p>
    041         *
    042         * @param count minimum number of iterations
    043         */
    044        void setMinimalIterationCount(int count);
    045
    046        /**
    047         * Get the lower limit for the number of iterations.
    048         *
    049         * @return the actual lower limit
    050         */
    051        int getMinimalIterationCount();
    052
    053        /**
    054         * Reset the lower limit for the number of iterations to the default.
    055         * <p>
    056         * The default value is supplied by the implementation.</p>
    057         *
    058         * @see #setMinimalIterationCount(int)
    059         */
    060        void resetMinimalIterationCount();
    061
    062        /**
    063         * Integrate the function in the given interval.
    064         *
    065         * @param min the lower bound for the interval
    066         * @param max the upper bound for the interval
    067         * @return the value of integral
    068         * @throws ConvergenceException if the maximum iteration count is exceeded
    069         * or the integrator detects convergence problems otherwise
    070         * @throws FunctionEvaluationException if an error occurs evaluating the
    071         * function
    072         * @throws IllegalArgumentException if min > max or the endpoints do not
    073         * satisfy the requirements specified by the integrator
    074         * @deprecated replaced by {@link #integrate(UnivariateRealFunction, double, double)}
    075         * since 2.0
    076         */
    077        @Deprecated
    078        double integrate(double min, double max)
    079            throws ConvergenceException, FunctionEvaluationException, IllegalArgumentException;
    080
    081        /**
    082         * Integrate the function in the given interval.
    083         *
    084         * @param f the integrand function
    085         * @param min the lower bound for the interval
    086         * @param max the upper bound for the interval
    087         * @return the value of integral
    088         * @throws ConvergenceException if the maximum iteration count is exceeded
    089         * or the integrator detects convergence problems otherwise
    090         * @throws FunctionEvaluationException if an error occurs evaluating the function
    091         * @throws IllegalArgumentException if min > max or the endpoints do not
    092         * satisfy the requirements specified by the integrator
    093         */
    094        double integrate(UnivariateRealFunction f, double min, double max)
    095            throws ConvergenceException, FunctionEvaluationException, IllegalArgumentException;
    096
    097        /**
    098         * Get the result of the last run of the integrator.
    099         *
    100         * @return the last result
    101         * @throws IllegalStateException if there is no result available, either
    102         * because no result was yet computed or the last attempt failed
    103         */
    104        double getResult() throws IllegalStateException;
    105
    106    }