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 /** 21 * Interface defining a visitor for matrix entries. 22 * 23 * @see DefaultRealMatrixChangingVisitor 24 * @version $Revision: 778191 $ $Date: 2009-05-24 12:44:52 -0400 (Sun, 24 May 2009) $ 25 * @since 2.0 26 */ 27 public interface RealMatrixChangingVisitor { 28 29 /** 30 * Start visiting a matrix. 31 * <p>This method is called once before any entry of the matrix is visited.</p> 32 * @param rows number of rows of the matrix 33 * @param columns number of columns of the matrix 34 * @param startRow Initial row index 35 * @param endRow Final row index (inclusive) 36 * @param startColumn Initial column index 37 * @param endColumn Final column index (inclusive) 38 */ 39 void start(int rows, int columns, 40 int startRow, int endRow, int startColumn, int endColumn); 41 42 /** 43 * Visit one matrix entry. 44 * @param row row index of the entry 45 * @param column column index of the entry 46 * @param value current value of the entry 47 * @return the new value to be set for the entry 48 * @throws MatrixVisitorException if something wrong occurs 49 */ 50 double visit(int row, int column, double value) 51 throws MatrixVisitorException; 52 53 /** 54 * End visiting a matrix. 55 * <p>This method is called once after all entries of the matrix have been visited.</p> 56 * @return the value that the <code>walkInXxxOrder</code> must return 57 */ 58 double end(); 59 60 }