1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package org.apache.commons.math.linear; 19 20 import org.apache.commons.math.FieldElement; 21 import org.apache.commons.math.linear.MatrixVisitorException; 22 23 /** 24 * Default implementation of the {@link FieldMatrixChangingVisitor} interface. 25 * <p> 26 * This class is a convenience to create custom visitors without defining all 27 * methods. This class provides default implementations that do nothing. 28 * </p> 29 * 30 * @param <T> the type of the field elements 31 * @version $Revision: 1073158 $ $Date: 2011-02-21 22:46:52 +0100 (lun. 21 fvr. 2011) $ 32 * @since 2.0 33 */ 34 public class DefaultFieldMatrixChangingVisitor<T extends FieldElement<T>> 35 implements FieldMatrixChangingVisitor<T> { 36 37 /** Zero element of the field. */ 38 private final T zero; 39 40 /** Build a new instance. 41 * @param zero additive identity of the field 42 */ 43 public DefaultFieldMatrixChangingVisitor(final T zero) { 44 this.zero = zero; 45 } 46 47 /** {@inheritDoc} */ 48 public void start(int rows, int columns, 49 int startRow, int endRow, int startColumn, int endColumn) { 50 } 51 52 /** {@inheritDoc} */ 53 public T visit(int row, int column, T value) throws MatrixVisitorException { 54 return value; 55 } 56 57 /** {@inheritDoc} */ 58 public T end() { 59 return zero; 60 } 61 62 } 63
