bdb78756f76deb7fb5f702b22fc0a1de0665957a
[scilab.git] / scilab / modules / simulated_annealing / help / en_US / utilities / accept_func_vfsa.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) 2010 - DIGITEO - Michael Baudin
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:ns4="http://www.w3.org/1999/xhtml" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:db="http://docbook.org/ns/docbook" xmlns:scilab="http://www.scilab.org" xml:id="accept_func_vfsa" xml:lang="en">
14     <refnamediv>
15         <refname>accept_func_vfsa</refname>
16         <refpurpose>The Very Fast Simulated Annealing acceptation function.</refpurpose>
17     </refnamediv>
18     <refsynopsisdiv>
19         <title>Calling Sequence</title>
20         <synopsis>Level = accept_func_vfsa(F_current, F_neigh, T)</synopsis>
21     </refsynopsisdiv>
22     <refsection>
23         <title>Arguments</title>
24         <variablelist>
25             <varlistentry>
26                 <term>F_current</term>
27                 <listitem>
28                     <para>the current function value</para>
29                 </listitem>
30             </varlistentry>
31             <varlistentry>
32                 <term>F_neigh</term>
33                 <listitem>
34                     <para>the function value of the neighbour</para>
35                 </listitem>
36             </varlistentry>
37             <varlistentry>
38                 <term>T</term>
39                 <listitem>
40                     <para>the current temperature</para>
41                 </listitem>
42             </varlistentry>
43             <varlistentry>
44                 <term>Level </term>
45                 <listitem>
46                     <para>the level of acceptation, in the interval [0,1].</para>
47                 </listitem>
48             </varlistentry>
49         </variablelist>
50     </refsection>
51     <refsection>
52         <title>Description</title>
53         <para>
54             The <literal>accept_func_vfsa</literal> provides the Very Fast Simulated Annealing acceptation function.
55         </para>
56         <para>
57             If the level computed by the acceptation function is higher 
58             than the generated uniform random number in the interval [0,1], then the neighbour is accepted.
59         </para>
60         <para>
61             The formula used in the implementation is the following.
62         </para>
63         <programlisting role="example"><![CDATA[ 
64 Level = 1 / (1 + exp(-(F_current - F_neigh)/max(T,%eps)));
65  ]]></programlisting>
66     </refsection>
67     <refsection role="see also">
68         <title>See Also</title>
69         <simplelist type="inline">
70             <member>
71                 <link linkend="accept_func_default">
72                     accept_func_default
73                 </link>
74             </member>
75         </simplelist>
76     </refsection>
77 </refentry>