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: 799857 $ $Date: 2009-08-01 09:07:12 -0400 (Sat, 01 Aug 2009) $
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) throws ConvergenceException, 
079            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
091         * function
092         * @throws IllegalArgumentException if min > max or the endpoints do not
093         * satisfy the requirements specified by the integrator
094         */
095        double integrate(UnivariateRealFunction f, double min, double max) throws ConvergenceException, 
096            FunctionEvaluationException, IllegalArgumentException;
097    
098        /**
099         * Get the result of the last run of the integrator.
100         * 
101         * @return the last result
102         * @throws IllegalStateException if there is no result available, either
103         * because no result was yet computed or the last attempt failed
104         */
105        double getResult() throws IllegalStateException;
106    
107    }