1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
<!DOCTYPE html>
<html>
<!-- Created by GNU Texinfo 7.1.1, https://www.gnu.org/software/texinfo/ -->
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Permutation Matrix Functions (GNU Octave (version 10.3.0))</title>
<meta name="description" content="Permutation Matrix Functions (GNU Octave (version 10.3.0))">
<meta name="keywords" content="Permutation Matrix Functions (GNU Octave (version 10.3.0))">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta name="viewport" content="width=device-width,initial-scale=1">
<link href="index.html" rel="start" title="Top">
<link href="Concept-Index.html" rel="index" title="Concept Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Function-Support.html" rel="up" title="Function Support">
<link href="Diagonal-Matrix-Functions.html" rel="prev" title="Diagonal Matrix Functions">
<style type="text/css">
<!--
a.copiable-link {visibility: hidden; text-decoration: none; line-height: 0em}
span:hover a.copiable-link {visibility: visible}
-->
</style>
<link rel="stylesheet" type="text/css" href="octave.css">
</head>
<body lang="en">
<div class="subsection-level-extent" id="Permutation-Matrix-Functions">
<div class="nav-panel">
<p>
Previous: <a href="Diagonal-Matrix-Functions.html" accesskey="p" rel="prev">Diagonal Matrix Functions</a>, Up: <a href="Function-Support.html" accesskey="u" rel="up">Functions That Are Aware of These Matrices</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<h4 class="subsection" id="Permutation-Matrix-Functions-1"><span>21.3.2 Permutation Matrix Functions<a class="copiable-link" href="#Permutation-Matrix-Functions-1"> ¶</a></span></h4>
<a class="index-entry-id" id="index-matrix_002c-permutation-functions"></a>
<a class="index-entry-id" id="index-permutation-matrix-functions"></a>
<p><em class="dfn">inv</em> and <em class="dfn">pinv</em> will invert a permutation matrix, preserving its
specialness. <em class="dfn">det</em> can be applied to a permutation matrix, efficiently
calculating the sign of the permutation (which is equal to the determinant).
</p>
<p>A permutation matrix can also be returned from the built-in functions
<em class="dfn">lu</em> and <em class="dfn">qr</em>, if a pivoted factorization is requested.
</p>
<p>The <em class="dfn">sparse</em> function will convert a permutation matrix efficiently to a
sparse matrix.
The <em class="dfn">find</em> function will also work efficiently with a permutation matrix,
making it possible to conveniently obtain the permutation indices.
</p>
</div>
</body>
</html>
|
