Help check: validate the help files on compilation against a derivated docbook schema
[scilab.git] / scilab / modules / elementary_functions / help / en_US / signalprocessing / ssrand.xml
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:ns5="http://www.w3.org/1999/xhtml" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:db="http://docbook.org/ns/docbook" version="5.0-subset Scilab" xml:id="ssrand" xml:lang="en">
14   <info>
15     <pubdate>$LastChangedDate$</pubdate>
16   </info>
17   <refnamediv>
18     <refname>ssrand</refname>
19     <refpurpose>random system generator</refpurpose>
20   </refnamediv>
21   <refsynopsisdiv>
22     <title>Calling Sequence</title>
23     <synopsis>sl=ssrand(nout,nin,nstate)
24 [sl,U]=ssrand(nout,nin,nstate,flag)</synopsis>
25   </refsynopsisdiv>
26   <refsection>
27     <title>Arguments</title>
28     <variablelist>
29       <varlistentry>
30         <term>nout</term>
31         <listitem>
32           <para>integer (number of output)</para>
33         </listitem>
34       </varlistentry>
35       <varlistentry>
36         <term>nin</term>
37         <listitem>
38           <para>integer (number of input)</para>
39         </listitem>
40       </varlistentry>
41       <varlistentry>
42         <term>nstate</term>
43         <listitem>
44           <para>integer (dimension of state-space)</para>
45         </listitem>
46       </varlistentry>
47       <varlistentry>
48         <term>flag</term>
49         <listitem>
50           <para>list made of one character string and one or several
51           integers</para>
52         </listitem>
53       </varlistentry>
54       <varlistentry>
55         <term>sl</term>
56         <listitem>
57           <para>list (<literal>syslin</literal> list)</para>
58         </listitem>
59       </varlistentry>
60       <varlistentry>
61         <term>U</term>
62         <listitem>
63           <para>square <literal>(nstate x nstate)</literal> nonsingular
64           matrix</para>
65         </listitem>
66       </varlistentry>
67     </variablelist>
68   </refsection>
69   <refsection>
70     <title>Description</title>
71     <para><literal>sl=ssrand(nout,nin,nstate)</literal> returns a random
72     strictly proper (<literal>D=0</literal>) state-space system of size
73     <literal>[nout,nint]</literal> represented by a <literal>syslin</literal>
74     list and with <literal>nstate</literal> state variables.</para>
75     <para><literal>[sl,U]=ssrand(nout,nin,nstate,flag)</literal> returns a
76     test linear system with given properties specified by
77     <literal>flag</literal>. <literal>flag</literal> can be one of the
78     following:</para>
79     <programlisting><![CDATA[ 
80 flag=list('co',dim_cont_subs)  
81 flag=list('uo',dim_unobs_subs)
82 flag=list('ncno',dim_cno,dim_ncno,dim_co,dim_nco)
83 flag=list('st',dim_cont_subs,dim_stab_subs,dim_stab0)  
84 flag=list('dt',dim_inst_unob,dim_instb0,dim_unobs)
85 flag=list('on',nr,ng,ng0,nv,rk)
86 flag=list('ui',nw,nwu,nwui,nwuis,rk)
87  ]]></programlisting>
88     <para>The complete description of the <literal>Sys</literal> is given in
89     the code of the <literal>ssrand</literal> function (in
90     <literal>SCI/modules/cacsd/macros/</literal>). For example with
91     <literal>flag=list('co',dim_cont_subs)</literal> a non-controllable system
92     is return and <literal>dim_cont_subs</literal> is the dimension of the
93     controllable subspace of <literal>Sys</literal>. The character strings
94     <literal>'co','uo','ncno','st','dt','on','ui'</literal> stand for
95     "controllable", "unobservable", "non-controllable-non-observable",
96     "stabilizable","detectable","output-nulling","unknown-input".</para>
97   </refsection>
98   <refsection>
99     <title>Examples</title>
100     <programlisting role="example"><![CDATA[ 
101 //flag=list('st',dim_cont_subs,dim_stab_subs,dim_stab0)  
102 //dim_cont_subs&lt;=dim_stab_subs&lt;=dim_stab0  
103 //pair (A,B) U-similar to:
104 //    [*,*,*,*;     [*;    
105 //    [0,s,*,*;     [0;
106 //A=  [0,0,i,*;   B=[0;
107 //    [0,0,0,u]     [0]
108 //     
109 // (A11,B1) controllable  s=stable matrix i=neutral matrix u=unstable matrix
110 [Sl,U]=ssrand(2,3,8,list('st',2,5,5));
111 w=ss2ss(Sl,inv(U)); //undo the random change of basis => form as above
112 [n,nc,u,sl]=st_ility(Sl);n,nc
113  ]]></programlisting>
114   </refsection>
115   <refsection role="see also">
116     <title>See Also</title>
117     <simplelist type="inline">
118       <member>
119         <link linkend="syslin">syslin</link>
120       </member>
121     </simplelist>
122   </refsection>
123 </refentry>