~ubuntu-branches/ubuntu/raring/scilab/raring-proposed

« back to all changes in this revision

Viewing changes to modules/linear_algebra/help/en_US/eigen/psmall.xml

  • Committer: Package Import Robot
  • Author(s): Sylvestre Ledru
  • Date: 2012-08-30 14:42:38 UTC
  • mfrom: (1.4.7)
  • Revision ID: package-import@ubuntu.com-20120830144238-c1y2og7dbm7m9nig
Tags: 5.4.0-beta-3-1~exp1
* New upstream release
* Update the scirenderer dep
* Get ride of libjhdf5-java dependency

Show diffs side-by-side

added added

removed removed

Lines of Context:
 
1
<?xml version="1.0" encoding="UTF-8"?>
 
2
<!--
 
3
 * Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
 
4
 * Copyright (C) 2008 - INRIA
 
5
 * 
 
6
 * This file must be used under the terms of the CeCILL.
 
7
 * This source file is licensed as described in the file COPYING, which
 
8
 * you should have received as part of this distribution.  The terms
 
9
 * are also available at    
 
10
 * http://www.cecill.info/licences/Licence_CeCILL_V2-en.txt
 
11
 *
 
12
 -->
 
13
<refentry xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:svg="http://www.w3.org/2000/svg" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:db="http://docbook.org/ns/docbook" version="5.0-subset Scilab" xml:lang="en" xml:id="psmall">
 
14
    <refnamediv>
 
15
        <refname>psmall</refname>
 
16
        <refpurpose> spectral projection</refpurpose>
 
17
    </refnamediv>
 
18
    <refsynopsisdiv>
 
19
        <title>Calling Sequence</title>
 
20
        <synopsis>[Q,M]=psmall(A,thres,flag)</synopsis>
 
21
    </refsynopsisdiv>
 
22
    <refsection>
 
23
        <title>Arguments</title>
 
24
        <variablelist>
 
25
            <varlistentry>
 
26
                <term>A</term>
 
27
                <listitem>
 
28
                    <para>real square matrix</para>
 
29
                </listitem>
 
30
            </varlistentry>
 
31
            <varlistentry>
 
32
                <term>thres</term>
 
33
                <listitem>
 
34
                    <para>real number</para>
 
35
                </listitem>
 
36
            </varlistentry>
 
37
            <varlistentry>
 
38
                <term>flag</term>
 
39
                <listitem>
 
40
                    <para>
 
41
                        character string (<literal>'c'</literal> or <literal>'d'</literal>)
 
42
                    </para>
 
43
                </listitem>
 
44
            </varlistentry>
 
45
            <varlistentry>
 
46
                <term>Q,M</term>
 
47
                <listitem>
 
48
                    <para>real matrices</para>
 
49
                </listitem>
 
50
            </varlistentry>
 
51
        </variablelist>
 
52
    </refsection>
 
53
    <refsection>
 
54
        <title>Description</title>
 
55
        <para>
 
56
            Projection on eigen-subspace associated with eigenvalues with real
 
57
            part &lt; <literal>thres</literal> (<literal>flag='c'</literal>) or
 
58
            with modulus &lt; <literal>thres</literal>
 
59
            (<literal>flag='d'</literal>).
 
60
        </para>
 
61
        <para>
 
62
            The projection is defined by <literal>Q*M</literal>, <literal>Q</literal> is
 
63
            full column rank, <literal>M</literal> is full row rank and
 
64
            <literal>M*Q=eye</literal>.
 
65
        </para>
 
66
        <para>
 
67
            If <literal>flag='c'</literal>, the eigenvalues of
 
68
            <literal>M*A*Q</literal> = eigenvalues of <literal>A</literal> with real part
 
69
            &lt; <literal>thres</literal>.
 
70
        </para>
 
71
        <para>
 
72
            If <literal>flag='d'</literal>, the eigenvalues of
 
73
            <literal>M*A*Q</literal> = eigenvalues of <literal>A</literal> with magnitude
 
74
            &lt; <literal>thres</literal>.
 
75
        </para>
 
76
        <para>
 
77
            If <literal>flag='c'</literal> and if <literal>[Q1,M1]</literal> =
 
78
            full rank factorization (<literal>fullrf</literal>) of
 
79
            <literal>eye()-Q*M</literal> then eigenvalues of <literal>M1*A*Q1</literal> =
 
80
            eigenvalues of <literal>A</literal> with real part &gt;=
 
81
            <literal>thres</literal>.
 
82
        </para>
 
83
        <para>
 
84
            If <literal>flag='d'</literal> and if <literal>[Q1,M1]</literal> =
 
85
            full rank factorization (<literal>fullrf</literal>) of
 
86
            <literal>eye()-Q*M</literal> then eigenvalues of <literal>M1*A*Q1</literal> =
 
87
            eigenvalues of <literal>A</literal> with magnitude &gt;=
 
88
            <literal>thres</literal>.
 
89
        </para>
 
90
    </refsection>
 
91
    <refsection>
 
92
        <title>Examples</title>
 
93
        <programlisting role="example"><![CDATA[ 
 
94
A=diag([1,2,3]);X=rand(A);A=inv(X)*A*X;
 
95
[Q,M]=psmall(A,2.5,'d');
 
96
spec(M*A*Q)
 
97
[Q1,M1]=fullrf(eye()-Q*M);
 
98
spec(M1*A*Q1)
 
99
 ]]></programlisting>
 
100
    </refsection>
 
101
    <refsection role="see also">
 
102
        <title>See Also</title>
 
103
        <simplelist type="inline">
 
104
            <member>
 
105
                <link linkend="pbig">pbig</link>
 
106
            </member>
 
107
            <member>
 
108
                <link linkend="proj">proj</link>
 
109
            </member>
 
110
            <member>
 
111
                <link linkend="projspec">projspec</link>
 
112
            </member>
 
113
        </simplelist>
 
114
    </refsection>
 
115
    <refsection>
 
116
        <title>Used Functions</title>
 
117
        <para>
 
118
            This function is  based on the ordered schur form (scilab
 
119
            function <literal>schur</literal>).
 
120
        </para>
 
121
    </refsection>
 
122
</refentry>