<?xml version="1.0" encoding="UTF-8"?>
<!--
 * Scilab ( http://www.scilab.org/ ) - This file is part of Scilab
 * Copyright (C) 2008 - INRIA
 *
 * Copyright (C) 2012 - 2016 - Scilab Enterprises
 *
 * 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.
 * This file was originally licensed under the terms of the CeCILL v2.1,
 * and continues to be available under such terms.
 * For more information, see the COPYING file which you should have received
 * 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:ns5="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="inttrap" xml:lang="en">
    <refnamediv>
        <refname>inttrap</refname>
        <refpurpose>integration of experimental data by trapezoidal
            interpolation
        </refpurpose>
    </refnamediv>
    <refsynopsisdiv>
        <title>Syntax</title>
        <synopsis>
            v = inttrap(s)
            v = inttrap(x, s)
        </synopsis>
    </refsynopsisdiv>
    <refsection>
        <title>Arguments</title>
        <variablelist>
            <varlistentry>
                <term>x</term>
                <listitem>
                    <para>vector of increasing x coordinate data. Default value is
                        <literal>1:size(s,'*')</literal>
                    </para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term>s</term>
                <listitem>
                    <para>vector of y coordinate data</para>
                </listitem>
            </varlistentry>
            <varlistentry>
                <term>v</term>
                <listitem>
                    <para>value of the integral</para>
                </listitem>
            </varlistentry>
        </variablelist>
    </refsection>
    <refsection>
        <title>Description</title>
        <para>Computes:</para>
        <para>
            <literal>s(i)=f(x(i))</literal> and <literal>x0=x(1)</literal>,
            <literal>x1=x(n)</literal>
        </para>
        <para>
            where <literal>f</literal> is a function described by a set of experimental values.
        </para>
        <para>Between mesh points function is interpolated linearly.</para>
    </refsection>
    <refsection>
        <title>Examples</title>
        <programlisting role="example"><![CDATA[
t = 0:0.1:%pi
inttrap(t,sin(t))
 ]]></programlisting>
    </refsection>
    <refsection role="see also">
        <title>See also</title>
        <simplelist type="inline">
            <member>
                <link linkend="intg">intg</link>
            </member>
            <member>
                <link linkend="intc">intc</link>
            </member>
            <member>
                <link linkend="intl">intl</link>
            </member>
            <member>
                <link linkend="integrate">integrate</link>
            </member>
            <member>
                <link linkend="intsplin">intsplin</link>
            </member>
            <member>
                <link linkend="splin">splin</link>
            </member>
        </simplelist>
    </refsection>
</refentry>
