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 * Interface defining a visitor for matrix entries. 024 * 025 * @param <T> the type of the field elements 026 * @version $Id: FieldMatrixChangingVisitor.java 1416643 2012-12-03 19:37:14Z tn $ 027 * @since 2.0 028 */ 029 public interface FieldMatrixChangingVisitor<T extends FieldElement<?>> { 030 /** 031 * Start visiting a matrix. 032 * <p>This method is called once before any entry of the matrix is visited.</p> 033 * @param rows number of rows of the matrix 034 * @param columns number of columns of the matrix 035 * @param startRow Initial row index 036 * @param endRow Final row index (inclusive) 037 * @param startColumn Initial column index 038 * @param endColumn Final column index (inclusive) 039 */ 040 void start(int rows, int columns, 041 int startRow, int endRow, int startColumn, int endColumn); 042 043 /** 044 * Visit one matrix entry. 045 * @param row row index of the entry 046 * @param column column index of the entry 047 * @param value current value of the entry 048 * @return the new value to be set for the entry 049 */ 050 T visit(int row, int column, T value); 051 052 /** 053 * End visiting a matrix. 054 * <p>This method is called once after all entries of the matrix have been visited.</p> 055 * @return the value that the <code>walkInXxxOrder</code> must return 056 */ 057 T end(); 058 }