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.FieldElement; 021 022 /** 023 * Interface defining a visitor for matrix entries. 024 * 025 * @param <T> the type of the field elements 026 * @version $Revision: 811685 $ $Date: 2009-09-05 13:36:48 -0400 (Sat, 05 Sep 2009) $ 027 * @since 2.0 028 */ 029 public interface FieldMatrixPreservingVisitor<T extends FieldElement<?>> { 030 031 /** 032 * Start visiting a matrix. 033 * <p>This method is called once before any entry of the matrix is visited.</p> 034 * @param rows number of rows of the matrix 035 * @param columns number of columns of the matrix 036 * @param startRow Initial row index 037 * @param endRow Final row index (inclusive) 038 * @param startColumn Initial column index 039 * @param endColumn Final column index (inclusive) 040 */ 041 void start(int rows, int columns, 042 int startRow, int endRow, int startColumn, int endColumn); 043 044 /** 045 * Visit one matrix entry. 046 * @param row row index of the entry 047 * @param column column index of the entry 048 * @param value current value of the entry 049 * @throws MatrixVisitorException if something wrong occurs 050 */ 051 void visit(int row, int column, T value) 052 throws MatrixVisitorException; 053 054 /** 055 * End visiting a matrix. 056 * <p>This method is called once after all entries of the matrix have been visited.</p> 057 * @return the value that the <code>walkInXxxOrder</code> must return 058 */ 059 T end(); 060 061 }