1 /*
2 * Copyright (C) 2012 Alberto Irurueta Carro (alberto@irurueta.com)
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package com.irurueta.algebra;
17
18 /**
19 * Enumerator indicating the possible methods available for matrix decomposition.
20 */
21 public enum DecomposerType {
22 /**
23 * Defines LU decomposition, which decomposes a matrix into upper (U) and
24 * lower (L) triangular matrices.
25 */
26 LU_DECOMPOSITION,
27
28 /**
29 * Defines QR decomposition, which decomposes a matrix into an orthogonal
30 * matrix (Q) and an upper triangular matrix (R).
31 */
32 QR_DECOMPOSITION,
33
34 /**
35 * Defines Economy QR decomposition, which is a faster version of QR
36 * decomposition. Notice that economy sized version only works for matrices
37 * having rows < columns, while Q is a rows-by-columns and R is
38 * columns-by-columns in size.
39 */
40 QR_ECONOMY_DECOMPOSITION,
41
42 /**
43 * Defines RQ decomposition, which decomposes a matrix into an upper
44 * diagonal matrix (R) and an orthogonal matrix (Q). RQ decomposition is
45 * very similar to QR, and it is related to it through transposition by
46 * reversing order of factors R and Q respect to QR decomposition.
47 */
48 RQ_DECOMPOSITION,
49
50 /**
51 * Defines Cholesky decomposition, which decomposes a square symmetric and
52 * positive definite matrix into a triangular factor (L) and its transposed
53 * (L').
54 */
55 CHOLESKY_DECOMPOSITION,
56
57 /**
58 * Defines Singular Value Decomposition, which decomposes any rectangular
59 * matrix into 2 unary matrices (U, V) and 1 diagonal matrix containing
60 * singular values (D).
61 */
62 SINGULAR_VALUE_DECOMPOSITION
63 }