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diff --git a/help/en_US/scilab2c_data_annotations.xml b/help/en_US/scilab2c_data_annotations.xml new file mode 100644 index 00000000..f8dc32c6 --- /dev/null +++ b/help/en_US/scilab2c_data_annotations.xml @@ -0,0 +1,157 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!-- + * Scilab ( http://www.scilab.org/ ) - This file is part of Scilab + * Copyright (C) DIGITEO - Bruno JOFRET + * + * This file is released into the public domain + * + --> +<refentry version="5.0-subset Scilab" xml:id="scilab2c_data_annotations" xml:lang="en" + xmlns="http://docbook.org/ns/docbook" + xmlns:xlink="http://www.w3.org/1999/xlink" + xmlns:svg="http://www.w3.org/2000/svg" + xmlns:ns3="http://www.w3.org/1999/xhtml" + xmlns:mml="http://www.w3.org/1998/Math/MathML" + xmlns:db="http://docbook.org/ns/docbook"> + <info> + <pubdate>$LastChangedDate$</pubdate> + </info> + + <refnamediv> + <refname>Scilab2C Data Annotations</refname> + + <refpurpose>Scilab to C Converter : Data Annotations How To</refpurpose> + </refnamediv> + + <refsection> + <title>Description</title> + <para> + Data annotations are used to define the size, type and precisions of variables and numbers used in the Scilab code. + </para> + <para> + By default Sci2C assumes the double precision, which is the default precision used by the Scilab language. + Actually the whole Scilab software only works with double precision. Pay attention that the computation done in Scilab and the C code generated with single precision can differ. + </para> + <para> + It is possible to force a default precision for each source file, by using a dedicated annotation that must be inserted after the function annotation section (Cf. <link linkend="scilab2c_functions_annotations">Function Annotation.</link>): + <programlisting role=""><![CDATA[//SCI2C: DEFAULT_PRECISION= precision]]></programlisting> + + This annotation specifies the default precision for all the data used in the function body. + Allowed settings for precision are: + <itemizedlist> + <listitem><literal><![CDATA[//SCI2C: DEFAULT_PRECISION= FLOAT]]></literal></listitem> + <listitem><literal><![CDATA[//SCI2C: DEFAULT_PRECISION= DOUBLE]]></literal></listitem> + </itemizedlist> + If not otherwise specified, the precision of the data will be float single and float double, respectively. + </para> + + <para> + It is also possible to force some variable having a certain type using functions : + <itemizedlist> + <listitem>float: forces a variable or a number or a matrix of numbers to be real float.</listitem> + <listitem>double: forces a variable or a number or a matrix of numbers to be real double.</listitem> + <listitem>floatcomplex: forces a variable or a number or a matrix of numbers to be complex float.</listitem> + <listitem>doublecomplex: forces a variable or a number or a matrix of numbers to be complex double.</listitem> + </itemizedlist> + </para> + + </refsection> + + <refsection> + <title>Example 1</title> + <programlisting role="example"><![CDATA[ +//SCI2C: DEFAULT_PRECISION= FLOAT +y = 10; +]]></programlisting> + This will generate a C code with the <literal>y</literal> variable declared as a scalar, real, float. + </refsection> + + <refsection> + <title>Example 2</title> + <programlisting role="example"><![CDATA[ +x = -10.3; +y = zeros(10,3); +z = double(-10.3); +]]></programlisting> + Assuming <literal><![CDATA[//SCI2C: DEFAULT_PRECISION]]></literal> is not present, the default precision will be <literal><![CDATA[DOUBLE]]></literal> + This will generate a C code with + <itemizedlist> + <listitem> + <literal>x</literal> as scalar real double. + </listitem> + <listitem> + <literal>y</literal> as 10 by 3 matrix of real double filled with zeros. + </listitem> + <listitem> + <literal>z</literal> as scalar real double. In this case the double specifier is redundant. + </listitem> + </itemizedlist> + </refsection> + + + <refsection> + <title>Example 3</title> + <programlisting role="example"><![CDATA[ +//SCI2C: DEFAULT_PRECISION= FLOAT +x = -10.3; +y = float(zeros(10,3)); +z = double(-10.3); +]]></programlisting> + This will generate a C code with + <itemizedlist> + <listitem> + <literal>x</literal> as scalar real float. + </listitem> + <listitem> + <literal>y</literal> as 10 by 3 matrix of real float filled with zeros. In this case the float specifier is redundant. + </listitem> + <listitem> + <literal>z</literal> as scalar real double. + </listitem> + </itemizedlist> + </refsection> + + + <refsection> + <title>Example 4</title> + <programlisting role="example"><![CDATA[ +//SCI2C: DEFAULT_PRECISION= FLOAT +x = double(3); +y = double(4); +z = x + y; +]]></programlisting> + This will generate a C code with + <itemizedlist> + <listitem> + <literal>x</literal> as scalar real double. + </listitem> + <listitem> + <literal>y</literal> as scalar real double. + </listitem> + <listitem> + <literal>z</literal> as scalar real double. According to the behaviour of <literal>+</literal> operator and due to the fact that <literal>x</literal> + and <literal>y</literal> are both in double precision, Scilab2C will set <literal>z</literal> with double precision. + </listitem> + </itemizedlist> + </refsection> + + <refsection> + <title>See Also</title> + <simplelist type="inline"> + <member> + <link linkend="scilab2c_annotations">Sciab2C Annotations</link>, + <link linkend="scilab2c">Scilab2C Code Generator</link> + </member> + </simplelist> + </refsection> + + + + <refsection> + <title>Authors</title> + <simplelist type="vert"> + <member>Bruno JOFRET</member> + <member>Raffaele NUTRICATO</member> + </simplelist> + </refsection> +</refentry> |