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.math4.legacy.linear;
19
20 import org.apache.commons.math4.legacy.exception.DimensionMismatchException;
21
22 /**
23 * Interface defining very basic matrix operations.
24 *
25 * @since 2.0
26 */
27 public interface AnyMatrix {
28 /**
29 * Indicates whether this is a square matrix.
30 *
31 * @return {@code true} if the number of rows is the same as the number of columns.
32 */
33 default boolean isSquare() {
34 return getRowDimension() == getColumnDimension();
35 }
36
37 /**
38 * Gets the number of rows.
39 *
40 * @return the number of rows.
41 */
42 int getRowDimension();
43
44 /**
45 * Gets the number of columns.
46 *
47 * @return the number of columns.
48 */
49 int getColumnDimension();
50
51 /**
52 * Checks that this matrix and the {@code other} matrix can be added.
53 *
54 * @param other Matrix to be added.
55 * @return {@code false} if the dimensions do not match.
56 */
57 default boolean canAdd(AnyMatrix other) {
58 return getRowDimension() == other.getRowDimension() &&
59 getColumnDimension() == other.getColumnDimension();
60 }
61
62 /**
63 * Checks that this matrix and the {@code other} matrix can be added.
64 *
65 * @param other Matrix to check.
66 * @throws IllegalArgumentException if the dimensions do not match.
67 */
68 default void checkAdd(AnyMatrix other) {
69 if (!canAdd(other)) {
70 throw new MatrixDimensionMismatchException(getRowDimension(), getColumnDimension(),
71 other.getRowDimension(), other.getColumnDimension());
72 }
73 }
74
75 /**
76 * Checks that this matrix can be multiplied by the {@code other} matrix.
77 *
78 * @param other Matrix to be added.
79 * @return {@code false} if the dimensions do not match.
80 */
81 default boolean canMultiply(AnyMatrix other) {
82 return getColumnDimension() == other.getRowDimension();
83 }
84
85 /**
86 * Checks that this matrix can be multiplied by the {@code other} matrix.
87 *
88 * @param other Matrix to check.
89 * @throws IllegalArgumentException if the dimensions do not match.
90 */
91 default void checkMultiply(AnyMatrix other) {
92 if (!canMultiply(other)) {
93 throw new DimensionMismatchException(getColumnDimension(),
94 other.getRowDimension());
95 }
96 }
97 }