<p>
  The LTPDA toolbox is object oriented and as such, extends the MATLAB object types to many others. All data processing is
  done using objects and methods of those classes.
</p>
<p>
  For full details of objects in MATLAB, refer to <a href="matlab:web(['jar:file:///' matlabroot '/help/techdoc/help.jar!/matlab_oop/ug_intropage.html'])">MATLAB Classes and Object-Oriented Programming</a>.
</p>
<a name="classes" id= "classes"><h3 class="title">LTPDA Classes</h3></a>

<p>
  Various classes make up the object-oriented infrastructure of LTPDA. The figure below shows all the classes in LTPDA.
  All classes are derived from the base class, <tt>ltpda_obj</tt>. The classes then fall into two main types deriving
  from the classes <tt>ltpda_nuo</tt> and <tt>ltpda_uo</tt>.
</p>
<br>
  <img src="images/objects_class_diagram.png" alt="LTPDA classes">
<br>
<p>
  The left branch, <tt>ltpda_nuo</tt>, are termed 'non-user objects'. These
  objects are not typically accessed or created by users. The right branch, <tt>ltpda_uo</tt>, are termed 'user objects'.
  These objects have a 'name' and a 'history' property which means that their processing history is tracked through all
  LTPDA algorithms. In addition, these 'user objects' can be saved to disk or to an LTPDA repository.
</p>
<p>
  The objects drawn in green are expected to be created by users in scripts or on the LTPDA GUI.
</p>


 <p>Details of each class are given in:</p>

  <table border="1" cellpadding="2" width="30%" bgcolor="#DDDDDD">
    <tr valign="top">
      <td><a href="class_desc_ao.html">analysis object class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_ssm.html">statespace model class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_rational.html">rational class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_parfrac.html">partial fraction class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_pzmodel.html">pole/zero model class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_miir.html">iir filter class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_mfir.html">fir filter class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_timespan.html">timespan class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_plist.html">parameter list class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_specwin.html">spectral window class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_time.html">time class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_pz.html">pole/zero class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_minfo.html">method info class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_history.html">history class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_provenance.html">provenance class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_param.html">parameter class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_unit.html">unit class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_cdata.html">constant data class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_xydata.html">xy data class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_tsdata.html">time-series data class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_fsdata.html">frequency-series data class</a></td>
    </tr>
    <tr valign="top">
      <td><a href="class_desc_xyzdata.html">xyz data class</a></td>
    </tr>
  </table>