* Get ride of the useless tag
[scilab.git] / scilab / modules / core / help / en_US / variables / clear.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" xmlns:scilab="http://www.scilab.org" xml:lang="en" xml:id="clear">
3     <refnamediv>
4         <refname>clear</refname>
5         <refpurpose>kills variables</refpurpose>
6     </refnamediv>
7     <refsynopsisdiv>
8         <title>Calling Sequence</title>
9         <synopsis>
10             clear a b c
11             clear('a','b','c')
12         </synopsis>
13     </refsynopsisdiv>
14     <refsection>
15         <title>Arguments</title>
16         <variablelist>
17             <varlistentry>
18                 <term>a,b,c...</term>
19                 <listitem>
20                     <para>variables of any type and size, but not protected</para>
21                 </listitem>
22             </varlistentry>
23         </variablelist>
24     </refsection>
25     <refsection>
26         <title>Description</title>
27         <para>
28             This command kills variables which are not protected.
29             It removes the named variables from the environment.
30             By itself <literal>clear</literal> kills all the variables except the variables
31             protected by <literal>predef</literal>. Thus the two commands <literal>predef(0)</literal> and <literal>clear</literal>
32             remove all the variables.
33         </para>
34         <para>
35             Normally, protected variables are standard libraries and variables with
36             the percent prefix.
37         </para>
38         <para>
39             Note the particular syntax <literal>clear a</literal> and <literal>clear('a')</literal>  
40             and not <literal>clear(a)</literal>. Note also that <literal>a=[]</literal> does not kill 
41             <literal>a</literal> but sets <literal>a</literal> to an empty matrix.
42         </para>
43         <para>
44             The command <literal>clear</literal> can kill nonexistent variables, i. e. 
45             <literal>clear</literal> kills nonexistent variables as if they exist.
46         </para>
47     </refsection>
48     <refsection role="see also">
49         <title>See Also</title>
50         <simplelist type="inline">
51             <member>
52                 <link linkend="predef">predef</link>
53             </member>
54             <member>
55                 <link linkend="who">who</link>
56             </member>
57         </simplelist>
58     </refsection>
59 </refentry>