<!-- Converted to DocBook/SGML by Kevin Conder -->
<refentry id="port">
  <refmeta>
    <refentrytitle>port</refentrytitle>
  </refmeta>
 
  <refnamediv>
    <refname>port</refname>
    <refpurpose>
      Applies portamento to a step-valued control signal.
      <indexterm id="IndexPort"><primary>port</primary></indexterm>
    </refpurpose>
  </refnamediv>
 
  <refsect1>
    <title>Description</title>
    <para>
      Applies portamento to a step-valued control signal.
    </para>
  </refsect1>
 
  <refsect1>
    <title>Syntax</title>
    <synopsis>kr <command>port</command> ksig, ihtim [, isig]</synopsis>
  </refsect1>
 
  <refsect1>
    <title>Initialization</title>
    <para>
      <emphasis>ihtim</emphasis> -- half-time of the function, in seconds.
    </para>

    <para>
      <emphasis>isig</emphasis> (optional, default=0) -- initial (i.e. previous) value for internal feedback. The default value is 0.
    </para>
  </refsect1>
 
  <refsect1>
    <title>Performance</title>
    <para>
      <emphasis>kr</emphasis> -- the output signal at control-rate.
    </para>

    <para>
      <emphasis>ksig</emphasis> -- the input signal at control-rate.
    </para>

    <para>
      <emphasis>port</emphasis> applies portamento to a step-valued control signal. At each new step value, <emphasis>ksig</emphasis> is low-pass filtered to move towards that value at a rate determined by <emphasis>ihtim</emphasis>. <emphasis>ihtim</emphasis> is the <quote>half-time</quote> of the function (in seconds), during which the curve will traverse half the distance towards the new value, then half as much again, etc., theoretically never reaching its asymptote. With <link linkend="portk"><citetitle>portk</citetitle></link>, the half-time can be varied at the control rate.
    </para>
  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para>
      <link linkend="areson"><citetitle>areson</citetitle></link>,
      <link linkend="aresonk"><citetitle>aresonk</citetitle></link>,
      <link linkend="atone"><citetitle>atone</citetitle></link>,
      <link linkend="atonek"><citetitle>atonek</citetitle></link>,
      <link linkend="portk"><citetitle>portk</citetitle></link>,
      <link linkend="reson"><citetitle>reson</citetitle></link>,
      <link linkend="resonk"><citetitle>resonk</citetitle></link>,
      <link linkend="tone"><citetitle>tone</citetitle></link>,
      <link linkend="tonek"><citetitle>tonek</citetitle></link>
    </para>
  </refsect1>
</refentry>
