scilab/modules/elementary_functions/help/en_US/trigonometry/cotd.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
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  16 <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="cotd" xml:lang="en">
  17     <refnamediv>
  18         <refname>cotd</refname>
  19         <refpurpose>element-wise cotangent function, argument in degree</refpurpose>
  20     </refnamediv>
  21     <refsynopsisdiv>
  22         <title>Syntax</title>
  23         <synopsis>y = cotd(x)</synopsis>
  24     </refsynopsisdiv>
  25     <refsection>
  26         <title>Arguments</title>
  27         <variablelist>
  28             <varlistentry>
  29                 <term>x</term>
  30                 <listitem>
  31                     <para>a real array.</para>
  32                 </listitem>
  33             </varlistentry>
  34             <varlistentry>
  35                 <term>y</term>
  36                 <listitem>
  37                     <para>a real array with same dimensions as
  38                         <varname>x</varname>.
  39                     </para>
  40                 </listitem>
  41             </varlistentry>
  42         </variablelist>
  43     </refsection>
  44     <refsection>
  45         <title>Description</title>
  46         <para>
  47             The entries of <varname>y</varname> are the cotangents of the
  48             corresponding entries of <varname>x</varname> supposed to be given in
  49             degree. <code>t=cos(x)./sin(x)</code>. For entries equal to
  50             <literal>n*180</literal> with <literal>n</literal> integers the results
  51             are infinite, whereas <code>cotg(n*%pi)</code> is large but finite
  52             because <constant>%pi</constant> cannot be represented exactly. For entries
  53             equal to <literal>n*90</literal> with <literal>n</literal> integers and
  54             odd the results are exactly <literal>0</literal>.
  55         </para>
  56     </refsection>
  57     <refsection>
  58         <title>Examples</title>
  59         <programlisting role="example"><![CDATA[
  60 x=[30 45 60 90];
  61 cotd(x)
  62  ]]></programlisting>
  63     </refsection>
  64     <refsection role="see also">
  65         <title>See also</title>
  66         <simplelist type="inline">
  67             <member>
  68                 <link linkend="cotg">cotg</link>
  69             </member>
  70         </simplelist>
  71     </refsection>
  72 </refentry>