<?xml version="1.0" encoding="utf-8"?>

<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="asech" xml:lang="ja">

    <refnamediv>

        <refname>asech</refname>

        <refpurpose>

            引数の要素毎の逆双曲線割線を計算する.

        </refpurpose>

    </refnamediv>

    <refsynopsisdiv>

        <title>呼び出し手順</title>

        <synopsis>y = asech(x)</synopsis>

    </refsynopsisdiv>

    <refsection>

        <title>引数</title>

        <variablelist>

            <varlistentry>

                <term>x</term>

                <listitem>

                    <para>実数または複素数の配列.</para>

                </listitem>

            </varlistentry>

            <varlistentry>

                <term>y</term>

                <listitem>

                    <para>実数または複素数の配列.</para>

                </listitem>

            </varlistentry>

        </variablelist>

    </refsection>

    <refsection>

        <title>説明</title>

        <para>

            引数の要素毎の逆双曲線割線を計算します.

            引数が実数で絶対値が1より小さい場合,結果は実数となります.

        </para>

        <para>

            以下の等式が成り立ちます: <code>asech(x) == acosh(1 ./ x) ==

                %i*csgn(%i*(1?1 ./ x))*asec(x) == csgn(%i*(1 ? 1 ./

                x))*(%pi/2*(%i+acsch(%i*x)))

            </code>

        </para>

    </refsection>

    <refsection>

        <title>例</title>

        <programlisting role="example"><![CDATA[
asech(1)
 ]]></programlisting>

    </refsection>

    <refsection role="see also">

        <title>参照</title>

        <simplelist type="inline">

            <member>

                <link linkend="sech">sech</link>

            </member>

        </simplelist>

    </refsection>

    <refsection>

        <title>参考文献</title>

        <simplelist type="vert">

            <member>Kahan, W., "Branch cuts for complex elementary functions, or,

                Much ado about nothing's sign bit", Proceedings of the joing IMA/SIAM

                conference on The State of the Art in Numerical Analysis, University of

                Birmingham, A. Iserles and M.J.D. Powell, eds, Clarendon Press, Oxford,

                1987, 165-210.

            </member>

        </simplelist>

    </refsection>

</refentry>

