2a7df97a16c451b2e4a7de4b9052d36837c12ac0
[scilab.git] / scilab / modules / cacsd / help / en_US / plot_display / nicholschart.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) 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"  xmlns:scilab="http://www.scilab.org" xml:lang="en" xml:id="nicholschart">
14     <refnamediv>
15         <refname>nicholschart</refname>
16         <refpurpose>Nichols chart</refpurpose>
17     </refnamediv>
18     <refsynopsisdiv>
19         <title>Calling Sequence</title>
20         <synopsis>nicholschart([ modules [,args [,colors]]])</synopsis>
21         <synopsis/>
22     </refsynopsisdiv>
23     <refsection>
24         <title>Arguments</title>
25         <variablelist>
26             <varlistentry>
27                 <term>modules</term>
28                 <listitem>
29                     <para>real vector ( modules (in dB))</para>
30                 </listitem>
31             </varlistentry>
32             <varlistentry>
33                 <term>args</term>
34                 <listitem>
35                     <para>real vector (phases (in degree))</para>
36                 </listitem>
37             </varlistentry>
38             <varlistentry>
39                 <term>colorss</term>
40                 <listitem>
41                     <para>a scalar or a vector, the color indices for isogain and iso phase curves</para>
42                 </listitem>
43             </varlistentry>
44         </variablelist>
45     </refsection>
46     <refsection>
47         <title>Description</title>
48         <para> plot the Nichols'chart: iso-module and iso-argument  contours of
49             <literal>y/(1+y)</literal> in <literal>y</literal> phase/gain plane
50         </para>
51         <para>
52             <literal>nicholschart</literal> may be used in cunjunction with
53             <link linkend="black">black</link>. 
54         </para>
55         <para>
56             The default values for <literal>modules</literal> and
57             <literal>args</literal> are respectively :
58         </para>
59         <para>
60             <literal>[-12 -8 -6 -5 -4 -3 -2 -1.4 -1 -.5 0.25 0.5 0.7 1 1.4 2 2.3 3 4 5 6 8 12]</literal>
61         </para>
62         <para>
63             <literal>[-(1:10) , -(20:10:160)]</literal>
64         </para>
65     </refsection>
66     <refsection>
67         <title>Examples</title>
68         <programlisting role="example"><![CDATA[
69     //Nichols chart
70     clf()
71     nicholschart(modules=[-6 -3 -1 1 3 6], args=[-1 -20 20 40 80 160 180]);
72     ]]></programlisting>
73         <para>
74             <scilab:image localized="true">
75                 nicholschart(modules=[-6 -3 -1 1 3 6], args=[-1 -20 20 40 80 160 180]);
76             </scilab:image>
77         </para>
78         <programlisting role="example"><![CDATA[
79     //Black diagram with Nichols chart as a grid
80     s=poly(0,'s');
81     Plant=syslin('c',16000/((s+1)*(s+10)*(s+100)));
82     //two degree of freedom PID
83     tau=0.2;xsi=1.2;
84     PID=syslin('c',(1/(2*xsi*tau*s))*(1+2*xsi*tau*s+tau^2*s^2));
85     clf();
86     black([Plant;Plant*PID ],0.01,100,["Plant";"Plant and PID corrector"]);
87     //move the caption in the lower rigth corner
88     ax=gca();Leg=ax.children(1);
89     Leg.legend_location="in_lower_right";
90     nicholschart(colors=color('light gray')*[1 1])
91     ]]></programlisting>
92         <para>
93             <scilab:image localized="true">
94                 s=poly(0,'s');
95                 Plant=syslin('c',16000/((s+1)*(s+10)*(s+100)));
96                 //two degree of freedom PID
97                 tau=0.2;xsi=1.2;
98                 PID=syslin('c',(1/(2*xsi*tau*s))*(1+2*xsi*tau*s+tau^2*s^2));
99                 clf();
100                 black([Plant;Plant*PID ],0.01,100,["Plant";"Plant and PID corrector"]);
101                 //move the caption in the lower rigth corner
102                 ax=gca();Leg=ax.children(1);
103                 Leg.legend_location="in_lower_right";
104                 nicholschart(colors=color('light gray')*[1 1])
105             </scilab:image>
106         </para>
107     </refsection>
108     <refsection role="see also">
109         <title>See Also</title>
110         <simplelist type="inline">
111             <member>
112                 <link linkend="black">black</link>
113             </member>
114             <member>
115                 <link linkend="nyquist">nyquist</link>
116             </member>
117             <member>
118                 <link linkend="hallchart">hallchart</link>
119             </member>
120         </simplelist>
121     </refsection>
122 </refentry>