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.math3.linear; 019 020 import org.apache.commons.math3.FieldElement; 021 022 /** 023 * Default implementation of the {@link FieldMatrixPreservingVisitor} 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 * @param <T> the type of the field elements 030 * @version $Id: DefaultFieldMatrixPreservingVisitor.java 1416643 2012-12-03 19:37:14Z tn $ 031 * @since 2.0 032 */ 033 public class DefaultFieldMatrixPreservingVisitor<T extends FieldElement<T>> 034 implements FieldMatrixPreservingVisitor<T> { 035 /** Zero element of the field. */ 036 private final T zero; 037 038 /** Build a new instance. 039 * @param zero additive identity of the field 040 */ 041 public DefaultFieldMatrixPreservingVisitor(final T zero) { 042 this.zero = zero; 043 } 044 045 /** {@inheritDoc} */ 046 public void start(int rows, int columns, 047 int startRow, int endRow, int startColumn, int endColumn) { 048 } 049 050 /** {@inheritDoc} */ 051 public void visit(int row, int column, T value) {} 052 053 /** {@inheritDoc} */ 054 public T end() { 055 return zero; 056 } 057 }