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* Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
* Copyright (C) 2006-2008 - INRIA
- *
* Copyright (C) 2012 - 2016 - Scilab Enterprises
+ * Copyright (C) 2020 - Samuel GOUGEON
*
* This file is hereby licensed under the terms of the GNU GPL v2.0,
* pursuant to article 5.3.4 of the CeCILL v.2.1.
* along with this program.
*
-->
-<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="setfield">
+<refentry xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink"
+ xmlns:svg="http://www.w3.org/2000/svg" xmlns:db="http://docbook.org/ns/docbook"
+ xmlns:scilab="http://www.scilab.org" xml:lang="en" xml:id="setfield">
<refnamediv>
<refname>setfield</refname>
- <refpurpose>list field insertion</refpurpose>
+ <refpurpose>change the value of an element of a mlist, tlist or list</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Syntax</title>
- <synopsis>a = setfield(i, x, l)</synopsis>
+ <synopsis>uL = setfield(a, v, L)</synopsis>
</refsynopsisdiv>
<refsection>
<title>Arguments</title>
<variablelist>
<varlistentry>
- <term>x</term>
+ <term>L</term>
<listitem>
- <para>a matrix of any possible types.</para>
+ a <literal>list</literal>, <literal>tlist</literal> or <literal>mlist</literal>
+ list: the list whose component must be changed.
+ <para/>
</listitem>
</varlistentry>
<varlistentry>
- <term>l</term>
+ <term>a</term>
<listitem>
- <para>
- a <literal>list</literal>, <literal>tlist</literal> or <literal>mlist</literal> variable.
- </para>
+ Address of the component to change. It can be either its field name
+ specified as a string, or its index specified as a positive integer.
+ See <link linkend="insertion">insertion</link> for more details.
+ <para/>
</listitem>
</varlistentry>
<varlistentry>
- <term>i</term>
+ <term>v</term>
<listitem>
- <para>
- a field index, see <link linkend="insertion">insertion</link> for more details.
- </para>
+ Any Scilab object: the value to assign.
+ <para/>
</listitem>
</varlistentry>
<varlistentry>
- <term>a</term>
+ <term>uL</term>
<listitem>
- <para>
- Updated variable.
- </para>
+ The updated list.
+ <para/>
</listitem>
</varlistentry>
</variablelist>
<refsection>
<title>Description</title>
<para>
- This function is an equivalent of <code>l(i)=x</code> syntax for field
- extraction with the only difference that it also applies to
- <literal>mlist</literal> objects.
+ <literal>L=setfield(a,v,L)</literal> addresses and changes the
+ i<superscript>th</superscript> element of a list, in a unified way
+ over lists, tlists and mlists.
+ </para>
+ <para>
+ For simple lists and for tlists, <literal>L=setfield(a,v,L)</literal>
+ is equivalent to <literal>L(a)=v</literal>, that is simpler and should be preferred.
+ The same stands for any mlist if the address <varname>a</varname> is a
+ field's name.
+ </para>
+ <para>
+ However, for any mlist L, if <literal>i</literal> is an index, the insertion
+ <literal>L(i)=v</literal> is not predefined, in order to let the user define
+ an overload implementing a matrix-oriented insertion, if required.
+ Yet <literal>setfield(i,v,L)</literal> is always defined, with the same meaning as
+ for other list and tlist types.
</para>
</refsection>
<refsection>
<title>Examples</title>
+ <para>
+ For a tlist, <literal>setfield(3, v, T)</literal> is equivalent to
+ <literal>T(3)=v</literal> :
+ </para>
<programlisting role="example"><![CDATA[
-l=list(1,'qwerw',%s)
-l(1)='Changed'
-l(0)='Added'
-l(6)=['one more';'added']
-l=setfield(5,"added by setfield", l)
+T = tlist(['V','a','b'], [%z (1-%z) %z^2], [%f %t %t]);
+// The insertion is predefined:
+T(3) = [%t %t %f];
+T(3)
+
+T = setfield(3, [%f %t %f], T);
+T(3)
]]></programlisting>
+ <screen><![CDATA[
+--> T = tlist(['V','a','b'], [%z (1-%z) %z^2], [%f %t %t]);
+--> // The insertion is predefined:
+--> T(3) = [%t %t %f];
+--> T(3)
+ ans =
+ T T F
+
+--> T = setfield(3, [%f %t %f], T);
+--> T(3)
+ ans =
+ F T F
+]]></screen>
+ <para>
+ For a mlist, there is no predefined indexed insertion routine, to
+ let the user define a matrix-oriented insertion overload if required.
+ </para>
+ <programlisting role="example"><![CDATA[
+M = mlist(['V','a','b'], [%z (1-%z) %z^2], [%f %t %t]);
+M.b = [%t %t %t];
+M.b // OK, while ...
+M(3) = [%f %t %f]; // => error
+
+// But a raw direct insertion with setfield() is always possible:
+M = setfield(3, [%t %f %t], M);
+getfield(3, M)
+ ]]></programlisting>
+ <screen><![CDATA[
+--> M = mlist(['V','a','b'], [%z (1-%z) %z^2], [%f %t %t]);
+--> M.b = [%t %t %t];
+--> M.b // OK, while ...
+ ans =
+ T T T
+
+--> M(3) = [%f %t %f]; // => error
+Function not defined for given argument type(s),
+ check arguments or define function %b_i_V for overloading.
+
+--> // But a raw direct insertion with setfield() is always possible:
+--> M = setfield(3, [%t %f %t], M);
+--> getfield(3, M)
+ ans =
+ T F T
+]]></screen>
</refsection>
<refsection role="see also">
<title>See also</title>
<member>
<link linkend="insertion">insertion</link>
</member>
+ <member>
+ <link linkend="getfield">getfield</link>
+ </member>
</simplelist>
</refsection>
<refsection>
<revision>
<revnumber>6.0.0</revnumber>
<revdescription>
- setfield returns variable updated instead of change it "in place".
+ <itemizedlist>
+ <listitem>
+ The updated list is now returned, instead of being changed "in place".
+ </listitem>
+ <listitem>
+ setfield() can no longer be used for cells arrays.
+ </listitem>
+ </itemizedlist>
</revdescription>
</revision>
</revhistory>
projects / scilab.git / blobdiff