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 22 /** 23 * Default implementation of the {@link FieldMatrixChangingVisitor} interface. 24 * <p> 25 * This class is a convenience to create custom visitors without defining all 26 * methods. This class provides default implementations that do nothing. 27 * </p> 28 * 29 * @param <T> the type of the field elements 30 * @version $Revision: 778191 $ $Date: 2009-05-24 12:44:52 -0400 (Sun, 24 May 2009) $ 31 * @since 2.0 32 */ 33 public class DefaultFieldMatrixChangingVisitor<T extends FieldElement<T>> 34 implements FieldMatrixChangingVisitor<T> { 35 36 /** Zero element of the field. */ 37 private final T zero; 38 39 /** Build a new instance. 40 * @param zero additive identity of the field 41 */ 42 public DefaultFieldMatrixChangingVisitor(final T zero) { 43 this.zero = zero; 44 } 45 46 /** {@inheritDoc} */ 47 public void start(int rows, int columns, 48 int startRow, int endRow, int startColumn, int endColumn) { 49 } 50 51 /** {@inheritDoc} */ 52 public T visit(int row, int column, T value) 53 throws MatrixVisitorException { 54 return value; 55 } 56 57 /** {@inheritDoc} */ 58 public T end() { 59 return zero; 60 } 61 62 }