    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
    018    package org.apache.commons.math.linear;
    019
    020    import org.apache.commons.math.linear.MatrixVisitorException;
    021
    022    /**
    023     * Default implementation of the {@link RealMatrixChangingVisitor} interface.
    024     * <p>
    025     * This class is a convenience to create custom visitors without defining all
    026     * methods. This class provides default implementations that do nothing.
    027     * </p>
    028     *
    029     * @version $Revision: 1073158 $ $Date: 2011-02-21 22:46:52 +0100 (lun. 21 f??vr. 2011) $
    030     * @since 2.0
    031     */
    032    public class DefaultRealMatrixChangingVisitor implements RealMatrixChangingVisitor {
    033
    034        /** {@inheritDoc} */
    035        public void start(int rows, int columns,
    036                          int startRow, int endRow, int startColumn, int endColumn) {
    037        }
    038
    039        /** {@inheritDoc} */
    040        public double visit(int row, int column, double value) throws MatrixVisitorException {
    041            return value;
    042        }
    043
    044        /** {@inheritDoc} */
    045        public double end() {
    046            return 0;
    047        }
    048
    049    }