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 DefaultRealMatrixPreservingVisitor
24 * @version $Revision: 778191 $ $Date: 2009-05-24 12:44:52 -0400 (Sun, 24 May 2009) $
25 * @since 2.0
26 */
27 public interface RealMatrixPreservingVisitor {
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 * @throws MatrixVisitorException if something wrong occurs
48 */
49 void visit(int row, int column, double value)
50 throws MatrixVisitorException;
51
52 /**
53 * End visiting a matrix.
54 * <p>This method is called once after all entries of the matrix have been visited.</p>
55 * @return the value that the <code>walkInXxxOrder</code> must return
56 */
57 double end();
58
59 }