* Bug #11670 to 11676 fixed - Add examples in the signal processing help pages.
[scilab.git] / scilab / modules / signal_processing / help / en_US / zpbutt.xml
1 <?xml version="1.0" encoding="UTF-8"?>
2 <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="zpbutt">
3     <refnamediv>
4         <refname>zpbutt</refname>
5         <refpurpose> Butterworth analog filter</refpurpose>
6     </refnamediv>
7     <refsynopsisdiv>
8         <title>Calling Sequence</title>
9         <synopsis>[pols,gain]=zpbutt(n,omegac)</synopsis>
10     </refsynopsisdiv>
11     <refsection>
12         <title>Arguments</title>
13         <variablelist>
14             <varlistentry>
15                 <term>n</term>
16                 <listitem>
17                     <para>integer (filter order)</para>
18                 </listitem>
19             </varlistentry>
20             <varlistentry>
21                 <term>omegac</term>
22                 <listitem>
23                     <para>real (cut-off frequency in Hertz)</para>
24                 </listitem>
25             </varlistentry>
26             <varlistentry>
27                 <term>pols</term>
28                 <listitem>
29                     <para>resulting poles of filter</para>
30                 </listitem>
31             </varlistentry>
32             <varlistentry>
33                 <term>gain</term>
34                 <listitem>
35                     <para>resulting gain of filter</para>
36                 </listitem>
37             </varlistentry>
38         </variablelist>
39     </refsection>
40     <refsection>
41         <title>Description</title>
42         <para>
43             computes the poles of a Butterworth analog
44             filter of order <literal>n</literal> and cutoff frequency omegac
45             transfer function H(s) is calculated by <literal>H(s)=gain/real(poly(pols,'s'))</literal>
46         </para>
47     </refsection>
48     <refsection>
49         <title>Examples</title>
50         <programlisting role="example"><![CDATA[ 
51 n=7;
52 omegac=3;
53 [pols,gain]=zpbutt(n,omegac)
54  ]]></programlisting>
55     </refsection>
56     
57 </refentry>