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

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

    <refnamediv>

        <refname>logm</refname>

        <refpurpose>正方行列の対数</refpurpose>

    </refnamediv>

    <refsynopsisdiv>

        <title>呼び出し手順</title>

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

    </refsynopsisdiv>

    <refsection>

        <title>引数</title>

        <variablelist>

            <varlistentry>

                <term>x</term>

                <listitem>

                    <para>正方行列</para>

                </listitem>

            </varlistentry>

        </variablelist>

    </refsection>

    <refsection>

        <title>説明</title>

        <para>

            <literal>logm(x)</literal> は

            <literal>x</literal>の対数行列です.

            <literal>x</literal>が正定でない場合には結果が

            複素数となります.

            <literal>x</literal>が対称行列の場合,

            掲載は Schur 形式で行われます.

            その他の場合,

            <literal>x</literal> は対角化可能と仮定されます.

            <literal>expm(logm(x))=x</literal>となります.

        </para>

    </refsection>

    <refsection>

        <title>例</title>

        <programlisting role="example"><![CDATA[
A=[1,2;3,4];
logm(A)
expm(logm(A))
A1=A*A';
logm(A1)
expm(logm(A1))
A1(1,1)=%i;
expm(logm(A1))
 ]]></programlisting>

    </refsection>

    <refsection role="see also">

        <title>参照</title>

        <simplelist type="inline">

            <member>

                <link linkend="expm">expm</link>

            </member>

            <member>

                <link linkend="log">log</link>

            </member>

        </simplelist>

    </refsection>

</refentry>

