<!-- Converted to DocBook/SGML by Kevin Conder -->
<refentry id="planet">
  <refmeta>
    <refentrytitle>planet</refentrytitle>
  </refmeta>
 
  <refnamediv>
    <refname>planet</refname>
    <refpurpose>
      Simulates a planet orbiting in a binary star system.
      <indexterm id="IndexPlanet"><primary>planet</primary></indexterm>
    </refpurpose>
  </refnamediv>
 
  <refsect1>
    <title>Description</title>
    <para>
      <emphasis>planet</emphasis> simulates a planet orbiting in a binary star system. The outputs are the x, y and z coordinates of the orbiting planet. It is possible for the planet to achieve escape velocity by a close encounter with a star. This makes this system somewhat unstable.
    </para>
  </refsect1>
 
  <refsect1>
    <title>Syntax</title>
    <synopsis>ax, ay, az <command>planet</command> kmass1, kmass2, ksep, ix, iy, iz, ivx, ivy, ivz, idelta [, ifriction]</synopsis>
  </refsect1>
 
  <refsect1>
    <title>Initialization</title>
    <para>
      <emphasis>ix, iy, iz</emphasis> -- the initial x, y and z coordinates of the planet
    </para>

    <para>
      <emphasis>ivx, ivy, ivz</emphasis> -- the initial velocity vector components for the planet.
    </para>

    <para>
      <emphasis>idelta</emphasis> -- the step size used to approximate the differential equation.
    </para>

    <para>
      <emphasis>ifriction</emphasis> (optional, default=0) -- a value for friction, which can used to keep the system from blowing up
    </para>
  </refsect1>
 
  <refsect1>
    <title>Performance</title>
    <para>
      <emphasis>ax, ay, az</emphasis> -- the output x, y, and z coodinates of the planet
    </para>

    <para>
      <emphasis>kmass1</emphasis> -- the mass of the first star
    </para>

    <para>
      <emphasis>kmass2</emphasis> -- the mass of the second star
    </para>
  </refsect1>

  <refsect1>
    <title>Examples</title>
    <para>
      Here is an example of the planet opcode. It uses the files <ulink url="examples/planet.orc"><citetitle>planet.orc</citetitle></ulink> and <ulink url="examples/planet.sco"><citetitle>planet.sco</citetitle></ulink>.

      <example>
        <title>Example of the planet opcode.</title>

        <programlisting>
<inlinemediaobject>
            <imageobject>
              <imagedata fileref="examples/planet.orc" format="linespecific">
            </imageobject>
          </inlinemediaobject>
        </programlisting>

        <programlisting>
<inlinemediaobject>
            <imageobject>
              <imagedata fileref="examples/planet.sco" format="linespecific">
            </imageobject>
          </inlinemediaobject>
        </programlisting>
      </example>
    </para>
  </refsect1>
 
  <refsect1>
    <title>Credits</title>
    <para>
      <simplelist>
        <member>Author: &namehans;</member>
        <member>December 1998</member>
      </simplelist>
    </para>

    <para>New in Csound version 3.50</para>
  </refsect1>
</refentry>
