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  <body><div class="book" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h1 class="title"><a
  id="id694810"></a>XMLlab-1.4 software getting started guide
  </h1></div><div><div class="authorgroup"><div class="author"><h3
  class="author"><span class="firstname">Stéphane</span> <span
  class="surname">Mottelet</span></h3><code class="email">&lt;<a
  href="mailto:stephane.mottelet@utc.fr">stephane.mottelet@utc.fr</a>&gt;</code></div><div
  class="author"><h3 class="author"><span class="firstname">André</span> <span
  class="surname">Pauss</span></h3><code class="email">&lt;<a
  href="mailto:andre.pauss@utc.fr">andre.pauss@utc.fr</a>&gt;</code></div><h3
  class="corpauthor">iode Conseil (<a href="http://www.iode-conseil.com"
  target="_top">www.iode-conseil.com</a>)</h3></div></div><div><p
  class="othercredit"><span class="othername">XMLlab is a project financed by
  the regional pole STEF of Picardie and the UNIT
  consortium.</span></p></div><div><p class="othercredit"><span
  class="othername"><a href="http://www.utc.fr/" target="_top"><img
  src="images/logos/UTC.png"></img></a><img src="images/logos/point.gif"
  width="10"></img><a href="http://www.unit-c.fr/" target="_top"><img
  src="images/logos/UNIT.gif"></img></a><img src="images/logos/point.gif"
  width="10"></img><a href="http://www.cr-picardie.fr/" target="_top"><img
  src="images/logos/cr_picardie.gif"></img></a><img
  src="images/logos/point.gif" width="10"></img><a
  href="http://www.recherche.gouv.fr/drrt/drrt.htm" target="_top"><img
  src="images/logos/DRRT.gif"></img></a><img src="images/logos/point.gif"
  width="10"></img><a href="http://www.iode-conseil.com" target="_top"><img
  src="images/logos/iode.png"></img></a></span></p></div></div><hr /></div><div
  class="toc"><p><b>Table of contents</b></p><dl>
      <dt><span class="chapter"><a href="#id867430">1.
      Introduction</a></span></dt>

      <dt><span class="chapter"><a href="#id867523">2. Installing the
      software</a></span></dt>

      <dd><dl>
          <dt><span class="section"><a href="#id867529">1. Installing Scilab
          3.1.1</a></span></dt>

          <dd><dl>
              <dt><span class="section"><a href="#id867542">1.1. Windows
              9X/NT/2000/XP</a></span></dt>

              <dt><span class="section"><a href="#id867878">1.2. Mac OS
              X.3</a></span></dt>

              <dt><span class="section"><a href="#id868102">1.3.
              Linux</a></span></dt>
            </dl></dd>

          <dt><span class="section"><a href="#id868250">2. Installing
          XMLlab-1.4</a></span></dt>

          <dd><dl>
              <dt><span class="section"><a href="#id868302">2.1. Windows
              9X/NT/2000/XP</a></span></dt>

              <dt><span class="section"><a href="#id868601">2.2. Mac OS X.3
              and Linux</a></span></dt>

              <dt><span class="section"><a href="#id869003">2.3. Uninstalling
              XMLlab-1.4</a></span></dt>

              <dt><span class="section"><a href="#id869024">2.4. XMLlab-1.4
              Installation test through a simulation exemple</a></span></dt>

              <dt><span class="section"><a href="#id869275">2.5. Uninstalling
              XMLlab-1.4</a></span></dt>
            </dl></dd>
        </dl></dd>

      <dt><span class="chapter"><a href="#id869304">3. Using the
      software</a></span></dt>

      <dd><dl>
          <dt><span class="section"><a href="#id869312"> </a></span></dt>

          <dt><span class="section"><a href="#id869312">1. Physical
          description of the simulation</a></span></dt>

          <dt><span class="section"><a href="#id870097">2. Logic of the
          description in XML of the simulation</a></span></dt>

          <dd><dl>
              <dt><span class="section"><a href="#id870137">2.1. General
              description of the simulation</a></span></dt>

              <dt><span class="section"><a href="#param_simulation">2.2.
              Simulation Parameters</a></span></dt>

              <dt><span class="section"><a href="#id870717">2.3. Simulation
              mathematicals models</a></span></dt>

              <dt><span class="section"><a href="#id871365">2.4. Simulation
              results display</a></span></dt>
            </dl></dd>

          <dt><span class="section"><a href="#id871604">3. Simulation
          enrichment &nbsp;example</a></span></dt>

          <dd><dl>
              <dt><span class="section"><a href="#id871705">3.1. <code
              class="code" /><ns:math overflow="scroll"
                  xmlns:ns="http://www.w3.org/1998/Math/MathML">
                  <ns:semantics definitionURL="" encoding="">
                    <ns:mrow>
                      <ns:msub>
                        <ns:mn>Creation of the <code
                        class="code">point</code>element allowing to settle
                        <ns:math overflow="scroll">
                            <ns:semantics definitionURL="" encoding="">
                              <ns:mrow>
                                <ns:msub>
                                  <ns:mi>θ</ns:mi>

                                  <ns:mn>0</ns:mn>
                                </ns:msub>
                              </ns:mrow>
                            </ns:semantics>
                          </ns:math></ns:mn>
                      </ns:msub>
                    </ns:mrow>

                    <ns:annotation encoding="MathType-MTEF" />
                  </ns:semantics>
                </ns:math></a></span></dt>

              <dt><span class="section"><a href="#id871848">3.2. Addition of
              the segment representing the forcing curve <code
              class="code">point0</code></a></span></dt>

              <dt><span class="section"><a href="#visu_point0">3.3.
              &nbsp;Addition of the <code class="code">point0
              <tt>visualization</tt></code></a></span></dt>

              <dt><span class="section"><a href="#id872033">3.4. Simulation
              new version test</a></span></dt>
            </dl></dd>
        </dl></dd>
    </dl></div><div class="list-of-figures"><p><b>List of figures</b></p><dl>
      <dt>2.1. <a href="#id869121">Parameters example of a pendulum
      simulation</a></dt>

      <dt>2.2. <a href="#id869171">Visualization of the pendulum simulation
      result</a></dt>

      <dt>3.1. <a href="#fig_pendule">The pendulum</a></dt>

      <dt>3.2. <a href="#fig_menu_parametres">Parameters menu entries of the
      Pendulum simulation</a></dt>

      <dt>3.3. <a href="#id870529">Resolution parameters data entry</a></dt>

      <dt>3.4. <a href="#id871575">Visualization of the pendulum simulation
      result</a></dt>

      <dt>3.5. <a href="#id872082"> <mml:math overflow="scroll"
          xmlns:mml="http://www.w3.org/1998/Math/MathML">
          <mml:semantics definitionURL="" encoding="">
            <mml:mrow>
              <mml:msub>
                <mml:mn>Interactive modification of the <ns:math
                    overflow="scroll"
                    xmlns:ns="http://www.w3.org/1998/Math/MathML">
                    <ns:semantics definitionURL="" encoding="">
                      <ns:mrow>
                        <ns:msub>
                          <ns:mi>θ</ns:mi>

                          <ns:mn>0 parameter</ns:mn>
                        </ns:msub>
                      </ns:mrow>
                    </ns:semantics>
                  </ns:math></mml:mn>
              </mml:msub>
            </mml:mrow>

            <mml:annotation encoding="MathType-MTEF" />
          </mml:semantics>
        </mml:math></a></dt>
    </dl></div><div class="list-of-equations"><p><b>List of
  equations</b></p><dl>
      <dt>3.1. <a href="#eq_pendule_reelle">Real equation of the pendulum
      movement</a></dt>

      <dt>3.2. <a href="#id869986">Linearized equation of the pendulum
      movement </a></dt>
    </dl></div><div class="chapter" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h2 class="title"><a
  id="id867430"></a>Chapter&nbsp;1.&nbsp;Introduction</h2></div></div></div><p><span
  class="emphasis"><em>XMLlab</em></span> is a toll, developed by Stéphane
  Mottelet and André Pauss at the Université de Technologie de Compiègne,
  allowing to generate simulations automatically. The description of a
  simulation is based on XML and includes the following elements: </p><div
  class="itemizedlist"><ul type="disc">
      <li><p>the mathematical models of objects (time dependant or not)
      describing the simulation,</p></li>

      <li><p>the description of physical parameters description involved in
      these models,</p></li>

      <li><p>the <b>IHM</b> allowing to act on these physical parameters and
      to visualize simulation.</p></li>
    </ul></div><p>The <span class="emphasis"><em>Scilab software
  </em></span>is used to calculate and visualize in real time the result of
  generated simulation, the IHM allowing to regulate the parameters of these
  one being delegated to <span class="emphasis"><em>Tcl/Tk</em></span>.</p><p
  class="alignleft">(sources : <code
  class="uri">http://xmllab.org/</code>, <code
  class="uri">http://scilabsoft.inria.fr/</code>, <code
  class="uri">http://wiki.tcl.tk/</code> and <code
  class="uri">http://www.tcl.tk/</code>)</p></div><div class="chapter"
  lang="fr" xml:lang="fr"><div class="titlepage"><div><div><h2
  class="title"><a id="id867523"></a>Chapter&nbsp;2.&nbsp;Installing the
  software</h2></div></div></div><div class="toc"><p><b>Table of
  contents</b></p><dl>
      <dt><span class="section"><a href="#id867529">1. Installing Scilab
      3.1.1</a></span></dt>

      <dd><dl>
          <dt><span class="section"><a href="#id867542">1.1. Windows
          9X/NT/2000/XP</a></span></dt>

          <dt><span class="section"><a href="#id867878">1.2. Mac OS
          X.3</a></span></dt>

          <dt><span class="section"><a href="#id868102">1.3.
          Linux</a></span></dt>
        </dl></dd>

      <dt><span class="section"><a href="#id868250">2. Installing
      XMLlab-1.4</a></span></dt>

      <dd><dl>
          <dt><span class="section"><a href="#id868302">2.1. Windows
          9X/NT/2000/XP</a></span></dt>

          <dt><span class="section"><a href="#id868601">2.2. Mac OS X.3 and
          Linux</a></span></dt>

          <dt><span class="section"><a href="#id869003">2.3. Uninstalling
          XMLlab-1.4</a></span></dt>

          <dt><span class="section"><a href="#id869024">2.4. Installation test
          of XMLlab-1.4 through a exemple of a simulation</a></span></dt>

          <dt><span class="section"><a href="#id869275">2.5. Uninstalling
          XMLlab-1.4</a></span></dt>
        </dl></dd>
    </dl></div><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h2 class="title" style="clear: both"><a
  id="id867529"></a>1.&nbsp;Installing Scilab
  3.1.1</h2></div></div></div><p>It is an indispensable prerequired to the
  installation and the use of XMLlab.</p><div class="section" lang="fr"
  xml:lang="fr"><div class="titlepage"><div><div><h3 class="title"><a
  id="id867542"></a>1.1.&nbsp;Windows 9X/NT/2000/XP</h3></div></div></div><div
  class="itemizedlist"><ul type="disc">
      <li><p class="alignleft">go to the page of Scilab download in the INRIA
      Web site: </p><p> <code
      class="uri">http://scilabsoft.inria.fr/download/index_download.php?page=release.html</code>.</p></li>

      <li><p class="alignleft">In the frame <span class="guilabel">For Windows
      9X/NT/2000/XP platforms</span>, click on the link <span
      class="guilabel">Scilab-3.1.1 installer for binary version</span>, that
      starts the downloading of the <code
      class="filename">scilab-3.1.1.exe</code> installation executable (also
      directly accessible from <code
      class="uri">http://scilabsoft.inria.fr/download/stable/scilab-3.1.1.exe</code>).</p></li>

      <li><p>Double-click on the executable <code
      class="filename">scilab-3.1.1.exe</code> to start the installation
      :</p><div class="itemizedlist"><ul type="circle">
          <li><p><span class="guilabel">Installation assistant language
          </span> : keep English and click on OK.</p></li>

          <li><p><span class="guilabel">Welcome to
          scilab-3.1.1</span>installation: close all the active applications
          and then click on Next button<span class="guibutton">
          &gt;</span>.</p></li>

          <li><p><span class="guilabel">License agreement</span> : read the
          license, tick on the box "I accept the terms of the contract" and
          click on Next button<span class="guilabel"></span><span
          class="guibutton"> &gt;</span>.</p></li>

          <li><p><span class="guilabel">Destination file</span>: keep the
          proposed emplacement or select another one by clicking the browse
          button ..., and select Next button <span class="guibutton">
          &gt;</span> (we will suppose in the continuation that the path
          chosen at this stage is <code class="filename">C:\Program
          Files\scilab-3.1.1</code>).</p></li>

          <li><p><span class="guilabel">Components to install</span>: don't
          change the proposed installation configuration (this one requires
          approximately 80 Mo disk space), and click on Next button<span
          class="guibutton"> &gt;</span>.</p></li>

          <li><p><span class="guilabel">Selection of the folder at the Start
          Menu</span> : keep the proposed name, or choose another one, and
          click on Next button<span class="guibutton"> &gt;</span>.</p></li>

          <li><p><span class="guilabel">Suplementary task</span> : keep the
          proposed choice (in particular those of the heading association
          Files<span class="guilabel">:</span>), or make others, and click on
          Next<span class="guibutton"> &gt;</span>.</p></li>

          <li><p><span class="guilabel">Ready to install</span>: Go through
          the synthesis of the installation options chosen, and click on
          Install<span class="guibutton"> &gt;</span>.</p></li>

          <li><p><span class="guilabel">Installation </span>: Wait during the
          installation process.</p></li>

          <li><p><span class="guilabel">Informations</span> : Go through and
          click on Next<span class="guibutton"> &gt;</span>.</p></li>

          <li><p>End of the installation of scilab-3.1.1 : choose or not to
          execute scilab immediately, and click on Finish button<span
          class="guibutton"> </span>.</p></li>
        </ul></div></li>
    </ul></div></div><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h3 class="title"><a
  id="id867878"></a>1.2.&nbsp;Mac OS X.3</h3></div></div></div><p>This
  installation requires the installation of <span
  class="emphasis"><em>fink</em></span> and of the Apple <span
  class="emphasis"><em>X11 </em></span>server:</p><div
  class="itemizedlist"><ul type="disc">
      <li><p class="alignleft">The installation and the use of <span
      class="emphasis"><em>fink</em></span> requires a minimal knowledge of
      the Unix system of Mac OS X , in particular the Terminal
      utilisation<span class="application"> </span>. The <span
      class="emphasis"><em>fink</em></span> download page <code
      class="uri">http://fink.sourceforge.net/download/index.php?phpLang=fr</code>
      explain in detail the procedure of <span
      class="emphasis"><em>fink</em></span> downloading.</p></li>

      <li><p class="alignleft">The Apple <span
      class="emphasis"><em>X11</em></span> server can be download from the
      page <code
      class="uri">http://www.apple.com/downloads/macosx/apple/x11formacosx.html</code>,
      by clicking on the downloading link. The installation doesn't shows
      particular difficulties.</p></li>
    </ul></div><p>Once these two installations are completed, the installation
  itself of Scilab can begin :</p><div class="itemizedlist"><ul type="disc">
      <li><p class="alignleft">Go to page <code
      class="uri">http://www.lmac.utc.fr/~mottelet/Darwin/</code> and click on
      the link <span class="guilabel">scilab-gtk_3.1.1_darwin.tgz</span>, wich
      starts the downloading of the compressed archives <code
      class="filename"><code
      class="uri">scilab-gtk_3.1.1_darwin.tgz</code></code> (also directly
      accessible from <code
      class="uri">http://www.lmac.utc.fr/~mottelet/Darwin/scilab-gtk_3.1.1_darwin.tgz</code>).</p></li>

      <li><p>Connect as root in a Terminal window and type the following
      commands<code class="systemitem"> </code>:</p><table border="0"
          class="simplelist" summary="Simple list">
          <tr>
            <td><span><strong class="command">tar xvzf
            scilab-gtk_3.1.1_darwin.tgz -C /</strong></span></td>
          </tr>

          <tr>
            <td><span><strong class="command">fink
            scanpackages</strong></span></td>
          </tr>

          <tr>
            <td><span><strong class="command">apt-get
            update</strong></span></td>
          </tr>

          <tr>
            <td><span><strong class="command">apt-get install
            scilab-gtk</strong></span></td>
          </tr>
        </table><p>The installation of scilab also requires then the automatic
      downloading and the installation of pre-required software (gnome,
      gtk...), answer <em class="parameter"><code>Yes </code></em>to the
      confirmation demand of installation of these packages.</p></li>

      <li><p>Also download the file <code class="filename">scilab.dmg</code>,
      that is a self-mounting archive that contains a small Mac OS X
      application allowing to start Scilab by double clicking on the
      icon.</p></li>
    </ul></div></div><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h3 class="title"><a
  id="id868102"></a>1.3.&nbsp;Linux</h3></div></div></div><div
  class="itemizedlist"><ul type="disc">
      <li><p class="alignleft">Go to the Scilab downloading page on the INRIA
      website : <code
      class="uri">http://scilabsoft.inria.fr/download/index_download.php?page=release.html</code>.</p></li>

      <li><p class="alignleft">In the frame <span class="guilabel">For
      GNU/Linux platforms</span>, click to the link <span
      class="guilabel">Scilab-3.1.1 binary file version for Linux</span>, that
      starts the downloading of the compressed archives <code
      class="filename"><code
      class="uri">scilab-3.1.1.bin.linux-i686.tar.gz</code></code> (also
      directly accessible from <code
      class="uri">http://scilabsoft.inria.fr/download/stable/scilab-3.1.1.bin.linux-i686.tar.gz</code>).</p></li>

      <li><p class="remark"><i><span class="remark"><span
      class="emphasis"><em>Caution</em></span>: This binary version having
      been compiled with <code class="filename">libc.so.6</code> related to
      <code class="filename">libc-2.3.X.so</code>, it could not work on old
      distributions of GNU/Linux for which <code
      class="filename">libc.so.6</code> is related to older library <code
      class="filename">libc</code>. If such were to be the case, it would be
      necessary to download <span class="guilabel">Scilab-3.1.1 source
      version</span> (<code
      class="uri">http://scilabsoft.inria.fr/download/stable/scilab-3.1.1.src.tar.gz</code>),
      decompress the archive and follow the procedure of compilation and
      installation described in the file <code
      class="filename">README_Unix</code>.</span></i></p></li>

      <li><p>Decompress the downloaded archive, place yourself in the
      repertory scilab-3.1.1 obtained and run the installation by typing the
      following command<code class="filename"> </code>: <span><strong
      class="command">make</strong></span></p></li>
    </ul></div></div></div><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h2 class="title" style="clear: both"><a
  id="id868250"></a>2.&nbsp;Installing XMLlab-1.4</h2></div></div></div><p>The
  first part of the procedure is independant of the installation platform
  :</p><div class="itemizedlist"><ul type="disc">
      <li><p>Go to the XMLlab website : <code
      class="uri">http://xmllab.org/</code>.</p></li>

      <li><p>Click the french version<span class="guilabel"> </span>, and then
      on the link <span class="guilabel">Installation</span>.</p></li>
    </ul></div><p>The second part is dependant of the relating platform
  :</p><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h3 class="title"><a
  id="id868302"></a>2.1.&nbsp;Windows 9X/NT/2000/XP</h3></div></div></div><div
  class="itemizedlist"><ul type="disc">
      <li><p>Click on the link <span
      class="guilabel">XMLlab-1.4-Win32.zip</span>, that starts the
      downloading of the installation executable <code
      class="filename">XMLlab-1.4-Win32.zip</code> (also directly accessible
      from <code
      class="uri">http:/xmllab.org/XMLlab-1.4-Win32.zip</code>).</p></li>

      <li><p>Decompress the downloaded archive and move the repertory <code
      class="filename">XMLlab</code> obtained towards its destination of
      installation <span class="emphasis"><em><code
      class="filename">rep_xmllab</code></em></span>, for example <code
      class="filename">C:\Program Files\XMLlab</code>.</p></li>

      <li><p class="remark"><i><span class="remark">Caution: if an older
      XMLlab version was already installed, it is preferable to uninstall
      it.</span></i></p><p>Start <span class="guimenuitem">Scilab</span> by
      double clicking on its icon or from the Start menu<span class="guimenu">
      </span>. Then choose the file<span class="guimenuitem">-&gt;Exec</span>
      and select the file <code class="filename">builder.sce</code> in the
      repertory <span class="emphasis"><em><code
      class="filename">rep_xmllab</code></em></span> and click on
      OK.</p><p><em><span class="remark">If you don't need to be able to
      execute your simulation outside of Scilab environement, you can pass
      directly to the section "Installation test".</span></em></p></li>

      <li><p>If you wish to be able to execute the simulations starting from
      command line DOS, add the following paths to the environment variable
      <code class="envar">Path</code> of the system :</p><div
      class="itemizedlist"><ul type="circle">
          <li><p><span class="emphasis"><em><code
          class="filename">rep_xmllab</code></em></span><code
          class="filename">\Windows NT\bin</code></p></li>

          <li><p><span class="emphasis"><em><code
          class="filename">rep_xmllab</code></em></span><code
          class="filename">\Windows NT\lib</code></p></li>
        </ul></div><p>To do so (under Windows NT/2000/XP) :</p><div
      class="itemizedlist"><ul type="circle">
          <li><p>Open the panel System configuration<span class="guilabel">
          </span>, click on the Advanced tab<span class="guilabel"> </span>,
          and on the Environment Variable button<span
          class="guilabel">...</span>,</p></li>

          <li><p>In the window opened, select in the zone: variable system ,
          the variable <span class="guilabel">Path line</span> then click on
          the button<span class="guilabel"> </span> <span
          class="guilabel">Modify...</span>,</p></li>

          <li><p>In the input opened box, position the cursor at the end of
          the field variable value: and add the paths by separating them by
          one "<code class="filename">;</code>",</p></li>

          <li><p>Click on <span class="guilabel">OK</span>, then again on
          <span class="guilabel">OK</span>, and a last time on <span
          class="guilabel">OK</span>.</p></li>
        </ul></div></li>
    </ul></div></div><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h3 class="title"><a
  id="id868601"></a>2.2.&nbsp;Mac OS X.3 and
  Linux</h3></div></div></div><p>The beginning of the installation is
  differentiated according to the platform :</p><div class="itemizedlist"><ul
      type="disc">
      <li><p>Mac OS X.3 :</p><div class="itemizedlist"><ul type="circle">
          <li><p class="alignleft">Click on the link <span
          class="guilabel">XMLlab-1.4-Darwin.tgz</span>, that starts the
          downloading of the <code class="filename"><code
          class="uri">XMLlab-1.4-Darwin.tgz</code></code> executable
          installation (also directly accessible from <code
          class="uri">http://xmllab.org/XMLlab-1.4-Darwin.tgz</code>).</p></li>

          <li><p>Decompress the downloaded archive and move the repertory
          <code class="filename">XMLlab</code> obtained towards its
          installation destination <span class="emphasis"><em><code
          class="filename">rep_xmllab</code></em></span>, for example <code
          class="filename">/Applications/XMLlab</code>.</p><p>Start <span
          class="guimenuitem">Scilab</span> by double-clicking on it's icon.
          Then choose <span class="guimenuitem">File-&gt;File
          Operations</span>, select the file <code
          class="filename">builder.sce</code> in the repertory <span
          class="emphasis"><em><code
          class="filename">rep_xmllab</code></em></span> and choose <span
          class="guimenu">exec</span> in the operations menu and click on
          OK.</p><p><em><span class="remark">If you don't need to be able to
          execute your simulation outside of Scilab environment, you can pass
          directly to the section "Installation test".</span></em></p></li>

          <li><p>If you wish to be able to execute the starting simulations
          from command line, add the next line to the file <code
          class="filename">.profile</code> being in your user
          repertory</p><table border="0" class="simplelist"
              summary="Simple list">
              <tr>
                <td><span><strong class="command">export
                PATH=</strong></span><span class="emphasis"><em><span><strong
                class="command">rep_xmllab</strong></span></em></span><span><strong
                class="command">/Darwin/bin:$PATH</strong></span></td>
              </tr>
            </table></li>
        </ul></div></li>

      <li><p>Linux :</p><div class="itemizedlist"><ul type="circle">
          <li><p class="alignleft">Click on the link <span
          class="guilabel">XMLlab-1.4-Linux.tgz</span>, that starts the
          downloading of the installation executable <code
          class="filename"><code
          class="uri">XMLlab-1.4-Linux.tgz</code></code> (also directly
          accessible from <code
          class="uri">http://xmllab.org/XMLlab-1.4-Linux.tgz</code>).</p></li>

          <li><p>Decompress the downloaded archive and move the repertory
          <code class="filename">XMLlab</code> obtained towards its
          installation destination <span class="emphasis"><em><code
          class="filename">rep_xmllab</code></em></span>, for example <code
          class="filename">/usr/local/XMLlab</code>.</p></li>

          <li><p class="remark"><i><span class="remark">Caution: if an older
          XMLlab version is already installed, it is preferable to uninstall
          it.</span></i></p><p>Enter the following commands in the Unix
          terminal (replace <span><strong class="command">fr</strong></span>
          for <span><strong class="command">eng</strong></span> to obtain
          anenglish installation) :</p><table border="0" class="simplelist"
              summary="Simple list">
              <tr>
                <td><span><strong class="command">cd </strong></span><span
                class="emphasis"><em><span><strong
                class="command">rep_xmllab</strong></span></em></span></td>
              </tr>

              <tr>
                <td><span><strong class="command">scilab -l fr -f
                builder.sce</strong></span></td>
              </tr>
            </table><p><em><span class="remark">If you don't need to be able
          to execute your simulation outside of Scilab environment, you can
          pass directly to the section "Installation
          test".</span></em></p></li>

          <li><p>If you wish to be able to execute the simulations starting
          from command line, add the next line to the file <code
          class="filename">.bash_profile</code> being in your user
          repertory</p><table border="0" class="simplelist"
              summary="Simple list">
              <tr>
                <td><span><strong class="command">export
                PATH=</strong></span><span class="emphasis"><em><span><strong
                class="command">rep_xmllab</strong></span></em></span><span><strong
                class="command">/Linux/bin:$PATH</strong></span></td>
              </tr>
            </table></li>
        </ul></div></li>
    </ul></div><p><em><span class="remark">The lines above describe an
  installation in the System Repertories, but it is completely possible to
  choose a repertory belonging to an ordinary user. When it is expected that
  several users use XMLlab on the same machine, is enough to proceed to the
  installation only once (by executing the script <code
  class="filename">builder.sce</code>). Then each new user will have to
  execute the script <code class="filename"><code
  class="exceptionname">setup.sce</code></code> located in the repertory <span
  class="emphasis"><em><code
  class="filename">rep_xmllab</code></em></span>.</span></em></p></div><div
  class="section" lang="fr" xml:lang="fr"><div class="titlepage"><div><div><h3
  class="title"><a id="id869003"></a>2.3.&nbsp;Uninstalling
  XMLlab-1.4</h3></div></div></div><p>To uninstall XMLlab choose the item from
  the <span class="guimenuitem">XMLlab menu-&gt;Uninstalling XMLlab</span>
  .</p></div><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h3 class="title"><a
  id="id869024"></a>2.4.&nbsp;Installation test of XMLlab-1.4 through a
  simulation example </h3></div></div></div><div class="itemizedlist"><ul
      type="disc">
      <li><p>Start <span><strong class="command">Scilab </strong></span>from
      the Start menu<span class="guilabel"> </span> (Windows) or from its icon
      (Mac OSX) or from the command line (Linux) : <span><strong
      class="command">scilab</strong></span>.</p></li>

      <li><p>Select <span class="guimenuitem">XMLlab-&gt;Demos XMLlab</span>,
      and choose then for an example <span class="guimenuitem">Physics</span>,
      and <span class="guimenuitem">Pendulum</span>.</p></li>

      <li><p>Two windows then appear :</p><div class="itemizedlist"><ul
          type="circle">
          <li><p>A window allowing to settle the pendulum simulation
          parameters (<span class="guimenuitem">Parameters-&gt;Parameters of a
          pendulum</span>) and those of the resolution of the differential
          equations allowing to calculate the angle of the pendulum compared
          to its equilibrium position, in relation to its length, to the
          initial angle and to the acceleration of the gravity (<span
          class="guimenuitem">Parameter-&gt;Resolution Parameter</span>s)
          :</p><div class="figure"><a id="id869121"></a><p
          class="title"><b>Figure&nbsp;2.1.&nbsp;Parameters example of a
          pendulum simulation </b></p><div class="screenshot"><div
          align="center" class="mediaobject"><img align="middle"
          alt="Paramètres de l'exemple de simulation d'un pendule"
          src="images/fen_pendule_param.jpg" /></div></div></div></li>

          <li><p>A window allowing to visualize the evolution, during a given
          interval of time, of the pendulum angle compared to its vertical
          position, according to whether this one is exactly calculated by
          solving the differential equations governing the pendulum behavior
          (Real solution) or that it is approached by a calculation making the
          assumption of its smallness (Linearized solution). :</p><div
          class="figure"><a id="id869171"></a><p
          class="title"><b>Figure&nbsp;2.2.&nbsp;Visualization of the pendulum
          simulation result </b></p><div class="screenshot"><div
          align="center" class="mediaobject"><img align="middle"
          alt="Visualisation du résultat de la simulation d'un pendule"
          src="images/fen_pendule_graph.jpg" /></div></div></div></li>
        </ul></div></li>

      <li><p>Let us specify that there are other possibilities to run a <span
      class="emphasis"><em>XMLlab simulation</em></span> :</p><div
      class="itemizedlist"><ul type="circle">
          <li><p>From <span class="emphasis"><em>Scilab</em></span>, via the
          menu <span class="guimenuitem">XMLlab-&gt;Demos XMLlab</span>,
          following-up the choice of the XML corresponding file.</p></li>

          <li><p>From the Unix or <span
          class="emphasis"><em>Scilab</em></span> commande line, position
          yourself in the repertory containing the XML file and type the
          following command:</p><table border="0" class="simplelist"
              summary="Simple list">
              <tr>
                <td><span><strong class="command">xmllab -run
                </strong></span><span class="emphasis"><em><span><strong
                class="command">nom_simulation</strong></span></em></span><span><strong
                class="command">.xml</strong></span></td>
              </tr>
            </table></li>
        </ul></div></li>
    </ul></div></div><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h3 class="title"><a
  id="id869275"></a>2.5.&nbsp;Uninstallating
  XMLlab-1.4</h3></div></div></div><p>Run <span><strong
  class="command">Scilab</strong></span> and select the entry menu <span
  class="guimenuitem">XMLlab-&gt;Uninstalling
  XMLlab</span>.</p></div></div></div><div class="chapter" lang="fr"
  xml:lang="fr"><div class="titlepage"><div><div><h2 class="title"><a
  id="id869304"></a>Chapter&nbsp;3.&nbsp;Using the
  software</h2></div></div></div><div class="toc"><p><b>Table of
  contents</b></p><dl>
      <dt><span class="section"><a href="#id869312">1. Physical description of
      the simulation</a></span></dt>

      <dt><span class="section"><a href="#id870097">2. Logic of the
      description in XML of the simulation</a></span></dt>

      <dd><dl>
          <dt><span class="section"><a href="#id870137">2.1. General
          description of the simulation</a></span></dt>

          <dt><span class="section"><a href="#param_simulation">2.2.
          Simulation Parameters</a></span></dt>

          <dt><span class="section"><a href="#id870717">2.3. Simulation
          mathematicals models</a></span></dt>

          <dt><span class="section"><a href="#id871365">2.4. Simulation
          results display</a></span></dt>
        </dl></dd>

      <dt><span class="section"><a href="#id871604">3. Simulation enrichment
      &nbsp;example</a></span></dt>

      <dd><dl>
          <dt><span class="section"><a href="#id871705">3.1. <code
          class="code" /><mml:math overflow="scroll"
              xmlns:mml="http://www.w3.org/1998/Math/MathML">
              <mml:semantics definitionURL="" encoding="">
                <mml:mrow>
                  <mml:msub>
                    <mml:mn>Creation of the <code
                    class="code">point</code>element allowing to settle
                    <ns:math overflow="scroll"
                        xmlns:ns="http://www.w3.org/1998/Math/MathML">
                        <ns:semantics definitionURL="" encoding="">
                          <ns:mrow>
                            <ns:msub>
                              <ns:mi>θ</ns:mi>

                              <ns:mn>0</ns:mn>
                            </ns:msub>
                          </ns:mrow>
                        </ns:semantics>
                      </ns:math></mml:mn>
                  </mml:msub>
                </mml:mrow>

                <mml:annotation encoding="MathType-MTEF" />
              </mml:semantics>
            </mml:math></a></span></dt>

          <dt><span class="section"><a href="#id871848">3.2. Addition of the
          segment representing the forcing curve <code
          class="code">point0</code></a></span></dt>

          <dt><span class="section"><a href="#visu_point0">3.3. &nbsp;Addition
          of the <code class="code">point0
          <tt>visualization</tt></code></a></span></dt>

          <dt><span class="section"><a href="#id872033">3.4. Simulation new
          version test</a></span></dt>
        </dl></dd>
    </dl></div><p>We will now present the bases XMLlab use. To do so, we will
  study the structure of the pendulum simulation previously seen and extend
  it, to add it a new functionality allowing to vary the initial angle of the
  pendulum by acting directly on the Scilab graph.</p><div class="section"
  lang="fr" xml:lang="fr"><div class="titlepage"><div><div><h2 class="title"
  style="clear: both"><a id="id869312"></a>1.&nbsp;Physical description of the
  simulation</h2></div></div></div><div class="figure"><a
  id="fig_pendule"></a><p class="title"><b>Figure&nbsp;3.1.&nbsp;The
  pendulum</b></p><div class="screenshot"><div align="center"
  class="mediaobject"><img align="middle" alt="Le pendule"
  src="images/pendule.jpg" /></div></div></div><p>Let us consider the pendulum
  represented on <a href="#fig_pendule"
  title="Figure&nbsp;3.1.&nbsp;Le pendule">Figure&nbsp;3.1, «&nbsp;The
  pendulum&nbsp;»</a>. This pendulum consists in a mass <span
  class="emphasis"><em>M</em></span> considered punctual and a rod length
  <span class="emphasis"><em>L</em></span> of negligible weight compared to
  <span class="emphasis"><em>M</em></span>. The weight is directed upwards
  according to a vertical axis. The pendulum movement is a planar movement of
  rotation center <span class="emphasis"><em>O</em></span>.</p><p>The position
  of the pendulum compared to its stable equilibrium position is characterized
  by the angle <mml:math overflow="scroll"
      xmlns:mml="http://www.w3.org/1998/Math/MathML">
      <mml:semantics definitionURL="" encoding="">
        <mml:mrow>
          <mml:mi>θ</mml:mi>

          <mml:mrow>
            <mml:mo>(</mml:mo>

            <mml:mi>t</mml:mi>

            <mml:mo>)</mml:mo>
          </mml:mrow>
        </mml:mrow>

        <mml:annotation encoding="MathType-MTEF" />
      </mml:semantics>
    </mml:math>, defined positively as indicated on the figure. It is
  considered that the pendulum is released without intial speed, starting from
  a position <mml:math overflow="scroll"
      xmlns:mml="http://www.w3.org/1998/Math/MathML">
      <mml:semantics definitionURL="" encoding="">
        <mml:mrow>
          <mml:msub>
            <mml:mi>θ</mml:mi>

            <mml:mn>0</mml:mn>
          </mml:msub>
        </mml:mrow>

        <mml:annotation encoding="MathType-MTEF" />
      </mml:semantics>
    </mml:math>.</p><p>We apply the fundamental principles of dynamics for the
  setting constituted by the rod and the mass. To obtain the equation of
  movement, just write the moment equations, for example in <span
      class="emphasis">
      <em>O</em>
    </span> : the dynamic moment at the point <span class="emphasis">
      <em>O</em>
    </span> of the pendulum is equal to the moment in <span class="emphasis">
      <em>O</em>
    </span> of external actions on the pendulum. The following equation is
  obtained : <mml:math overflow="scroll"
      xmlns:mml="http://www.w3.org/1998/Math/MathML">
      <mml:semantics definitionURL="" encoding="">
        <mml:mrow>
          <mml:mi>J</mml:mi>

          <mml:mover accent="true">
            <mml:mi>θ</mml:mi>

            <mml:mo>¨</mml:mo>
          </mml:mover>

          <mml:mrow>
            <mml:mo>(</mml:mo>

            <mml:mi>t</mml:mi>

            <mml:mo>)</mml:mo>
          </mml:mrow>

          <mml:mo>=</mml:mo>

          <mml:mo>−</mml:mo>

          <mml:mi>M</mml:mi>

          <mml:mi>g</mml:mi>

          <mml:mi>L</mml:mi>

          <mml:mi>sin</mml:mi>

          <mml:mo>⁡</mml:mo>

          <mml:mi>θ</mml:mi>

          <mml:mrow>
            <mml:mo>(</mml:mo>

            <mml:mi>t</mml:mi>

            <mml:mo>)</mml:mo>
          </mml:mrow>
        </mml:mrow>

        <mml:annotation encoding="MathType-MTEF" />
      </mml:semantics>
    </mml:math> where <mml:math overflow="scroll"
      xmlns:mml="http://www.w3.org/1998/Math/MathML">
      <mml:semantics definitionURL="" encoding="">
        <mml:mrow>
          <mml:mi>J</mml:mi>

          <mml:mo>=</mml:mo>

          <mml:mi>M</mml:mi>

          <mml:msup>
            <mml:mi>L</mml:mi>

            <mml:mn>2</mml:mn>
          </mml:msup>
        </mml:mrow>

        <mml:annotation encoding="MathType-MTEF" />
      </mml:semantics>
    </mml:math> is the moment of inertia of the pendulum at the point <span
      class="emphasis">
      <em>O</em>
    </span>. After simplification, the following differential equation is
  obtained :</p><div class="equation"><a id="eq_pendule_reelle" /><p
      class="title">
      <b>Equation&nbsp;3.1.&nbsp;Real equation of the pendulum movement</b>
    </p><mml:math display="block" overflow="scroll"
      xmlns:mml="http://www.w3.org/1998/Math/MathML">
      <mml:semantics definitionURL="" encoding="">
        <mml:mrow>
          <mml:mrow>
            <mml:mo />

            <mml:mtable columnalign="left">
              <mml:mtr>
                <mml:mtd>
                  <mml:mover accent="true">
                    <mml:mi>θ</mml:mi>

                    <mml:mo>¨</mml:mo>
                  </mml:mover>

                  <mml:mrow>
                    <mml:mo>(</mml:mo>

                    <mml:mi>t</mml:mi>

                    <mml:mo>)</mml:mo>
                  </mml:mrow>

                  <mml:mo>=</mml:mo>

                  <mml:mo>−</mml:mo>

                  <mml:mfrac>
                    <mml:mi>g</mml:mi>

                    <mml:mi>L</mml:mi>
                  </mml:mfrac>

                  <mml:mi>sin</mml:mi>

                  <mml:mo>⁡</mml:mo>

                  <mml:mi>θ</mml:mi>

                  <mml:mrow>
                    <mml:mo>(</mml:mo>

                    <mml:mi>t</mml:mi>

                    <mml:mo>)</mml:mo>
                  </mml:mrow>

                  <mml:mo>,</mml:mo>

                  <mml:mtext> </mml:mtext>

                  <mml:mi>t</mml:mi>

                  <mml:mo>∈</mml:mo>

                  <mml:mrow>
                    <mml:mo>[</mml:mo>

                    <mml:mrow>
                      <mml:mn>0,</mml:mn>

                      <mml:mi>T</mml:mi>
                    </mml:mrow>

                    <mml:mo>]</mml:mo>
                  </mml:mrow>
                </mml:mtd>
              </mml:mtr>

              <mml:mtr>
                <mml:mtd>
                  <mml:mi>θ</mml:mi>

                  <mml:mo stretchy="false">(</mml:mo>

                  <mml:mn>0</mml:mn>

                  <mml:mo stretchy="false">)</mml:mo>

                  <mml:mo>=</mml:mo>

                  <mml:msub>
                    <mml:mi>θ</mml:mi>

                    <mml:mrow>
                      <mml:mn>0,</mml:mn>
                    </mml:mrow>
                  </mml:msub>
                </mml:mtd>
              </mml:mtr>

              <mml:mtr>
                <mml:mtd>
                  <mml:mover accent="true">
                    <mml:mi>θ</mml:mi>

                    <mml:mo>˙</mml:mo>
                  </mml:mover>

                  <mml:mo stretchy="false">(</mml:mo>

                  <mml:mn>0</mml:mn>

                  <mml:mo stretchy="false">)</mml:mo>

                  <mml:mo>=</mml:mo>

                  <mml:mn>0.</mml:mn>
                </mml:mtd>
              </mml:mtr>
            </mml:mtable>
          </mml:mrow>
        </mml:mrow>

        <mml:annotation encoding="MathType-MTEF" />
      </mml:semantics>
    </mml:math></div><p>if <mml:math overflow="scroll"
      xmlns:mml="http://www.w3.org/1998/Math/MathML">
      <mml:semantics definitionURL="" encoding="">
        <mml:mrow>
          <mml:mi>θ</mml:mi>

          <mml:mrow>
            <mml:mo>(</mml:mo>

            <mml:mi>t</mml:mi>

            <mml:mo>)</mml:mo>
          </mml:mrow>
        </mml:mrow>

        <mml:annotation encoding="MathType-MTEF" />
      </mml:semantics>
    </mml:math> is low, we have: <mml:math overflow="scroll"
      xmlns:mml="http://www.w3.org/1998/Math/MathML">
      <mml:semantics definitionURL="" encoding="">
        <mml:mrow>
          <mml:mi>sin</mml:mi>

          <mml:mo>⁡</mml:mo>

          <mml:mi>θ</mml:mi>

          <mml:mrow>
            <mml:mo>(</mml:mo>

            <mml:mi>t</mml:mi>

            <mml:mo>)</mml:mo>
          </mml:mrow>

          <mml:mo>≃</mml:mo>

          <mml:mi>θ</mml:mi>

          <mml:mrow>
            <mml:mo>(</mml:mo>

            <mml:mi>t</mml:mi>

            <mml:mo>)</mml:mo>
          </mml:mrow>
        </mml:mrow>

        <mml:annotation encoding="MathType-MTEF" />
      </mml:semantics>
    </mml:math>, that enables us to integrate the earlier differential
  equation. We have then:</p><div class="equation"><a id="id869986" /><p
      class="title">
      <b>Equation&nbsp;3.2.Linearized equation of the pendulum movement </b>
    </p><mml:math display="block" overflow="scroll"
      xmlns:mml="http://www.w3.org/1998/Math/MathML">
      <mml:semantics definitionURL="" encoding="">
        <mml:mrow>
          <mml:mi>φ</mml:mi>

          <mml:mrow>
            <mml:mo>(</mml:mo>

            <mml:mi>t</mml:mi>

            <mml:mo>)</mml:mo>
          </mml:mrow>

          <mml:mo>=</mml:mo>

          <mml:msub>
            <mml:mi>θ</mml:mi>

            <mml:mn>0</mml:mn>
          </mml:msub>

          <mml:mi>cos</mml:mi>

          <mml:mo>⁡</mml:mo>

          <mml:mrow>
            <mml:mo>(</mml:mo>

            <mml:mrow>
              <mml:msqrt>
                <mml:mrow>
                  <mml:mfrac>
                    <mml:mi>g</mml:mi>

                    <mml:mi>L</mml:mi>
                  </mml:mfrac>
                </mml:mrow>
              </mml:msqrt>

              <mml:mtext> </mml:mtext>

              <mml:mtext> </mml:mtext>

              <mml:mi>t</mml:mi>
            </mml:mrow>

            <mml:mo>)</mml:mo>
          </mml:mrow>

          <mml:mo>.</mml:mo>
        </mml:mrow>

        <mml:annotation encoding="MathType-MTEF" />
      </mml:semantics>
    </mml:math></div></div><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h2 class="title" style="clear: both"><a
  id="id870097"></a>2.&nbsp;Logic of the description in XML of the
  simulation</h2></div></div></div><p> We will show how this simulation is
  translated into a XML file that the tool <span
  class="emphasis"><em>XMLlab</em></span> will use to generate a simulation
  executed by <span class="emphasis"><em>Scilab</em></span>. The XML file will
  be shown in its textual form, and occasionally also such as it appears at
  the time of its edition with the software <span class="emphasis"><em>XMLMind
  XML Editor</em></span> (<span class="emphasis"><em>xxe</em></span>, cf.
  <code class="uri">http://www.xmlmind.com/xmleditor/</code>). Such a software
  allows a good visualization of the structure of a file XML, as its
  modification is facilitated by the fact that it permanently presents; the
  totaly of the tags which can be added to each place, as well as the totaly
  of the attributes of a given tag, with if necessary their various allowed
  values.</p><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h3 class="title"><a
  id="id870137"></a>2.1.&nbsp;General description of the
  simulation</h3></div></div></div><p>The first two lines of the file allows
  to associate the DTD of XMLlab to XML file and they are identical for any
  simulation. They must be modified only at the time of an XMLlab update
  implying an evolution of the DTD (here in version 1.4).</p><pre
  class="programlisting">&lt;?xml version="1.0" encoding="ISO-8859-1"?&gt;
&lt;!DOCTYPE simulation PUBLIC "-//UTC//DTD XMLlab V1.4//FR" "http://xmllab.org/dtd/1.4/simulation.dtd"&gt;</pre><p>The
  following lines make possible to specify the title of simulation, its
  author, as well as the keywords related to it :</p><pre
  class="programlisting">&lt;simulation&gt;
  &lt;header&gt;
    &lt;title&gt;Pendulum&lt;/title&gt;
    &lt;author&gt;Please set author's name&lt;/author&gt;
    &lt;keywords&gt;simulation,scilab,xml&lt;/keywords&gt;
  &lt;/header&gt;
  ...
&lt;/simulation&gt; </pre></div><div class="section" lang="fr"
  xml:lang="fr"><div class="titlepage"><div><div><h3 class="title"><a
  id="param_simulation"></a>2.2.&nbsp;Simulation
  Parameters</h3></div></div></div><p>The Simulation Parameters can be grouped
  in several sections, every section giving place to a different entry from
  the Simulation Parameters menu, as shown in the following figure :</p><div
  class="figure"><a id="fig_menu_parametres"></a><p
  class="title"><b>Figure&nbsp;3.2 Parameters menu entries of the Pendulum
  simulation </b></p><div class="screenshot"><div align="center"
  class="mediaobject"><img align="middle"
  alt="Entrées du menu Paramètres de la simulation du pendule"
  src="images/fen_pendule_menu_param.jpg" /></div></div></div><p>The choice of
  an entry then causes, the display of the corresponding parameters in the
  window . The following lines introduce and name the sections of parameters
  :</p><pre class="programlisting">  &lt;parameters&gt;
    &lt;section&gt;
      &lt;title&gt;Pendulum Parameters&lt;/title&gt;
      ...
    &lt;/section&gt;
    &lt;section&gt;
      &lt;title&gt;Resolution Parameters&lt;/title&gt;
      ...
    &lt;/section&gt;
  &lt;/parameters&gt;</pre><p>We are now going to describe in detail the
  statement of the parameters of eacg section, which the corresponding lines
  appear after the tag <code class="code">&lt;title&gt;</code> in question
  :</p><div class="itemizedlist"><ul type="disc">
      <li><p><span class="bold"><strong>Pendulum Parameters</strong></span> :
      The following lines describe each one of these parameters which their
      entry is made in the window illustrated by <a
      href="#fig_menu_parametres"
      title="Figure&nbsp;3.2.&nbsp;Entrées du menu Paramètres de la           simulation du pendule">Figure&nbsp;3.2,
      «&nbsp;Parameters menu entries of the Pendulum simulation<span
      class="guimenu"> </span>»</a> :</p><div class="itemizedlist"><ul
          type="circle">
          <li><p>Length <span class="emphasis"><em>L</em></span> of pendulum
          :</p><div class="informaltable"><table border="0">
              <colgroup>
                <col />

                <col />
              </colgroup>

              <tbody>
                <tr>
                  <td><div><img src="images/xxe_param_L.jpg"></img></div></td>

                  <td><pre class="programlisting">      &lt;scalar label="L"
              unit="m"
              widget="entry"&gt;
        &lt;name&gt;Length of the pendulum&lt;/name&gt;
        &lt;value&gt;1&lt;/value&gt;
      &lt;/scalar&gt;</pre><p>The parameter value is entered via a text field
                  and its initial value is 1. The attribute label is used to
                  refer to this parameter in the continuation<code
                  class="code"> </code>(<code class="code">L</code>).</p></td>
                </tr>
              </tbody>
            </table></div></li>

          <li><p>Initial angle <mml:math overflow="scroll"
              xmlns:mml="http://www.w3.org/1998/Math/MathML">
              <mml:semantics definitionURL="" encoding="">
                <mml:mrow>
                  <mml:msub>
                    <mml:mi>θ</mml:mi>

                    <mml:mn>0</mml:mn>
                  </mml:msub>
                </mml:mrow>

                <mml:annotation encoding="MathType-MTEF" />
              </mml:semantics>
            </mml:math> of the pendulum :</p><div class="informaltable"><table
              border="0">
              <colgroup>
                <col />

                <col />
              </colgroup>

              <tbody>
                <tr>
                  <td><div><img
                  src="images/xxe_param_theta_0.jpg"></img></div></td>

                  <td><pre class="programlisting">      &lt;scalar increment="0.001"
              label="theta_0"
              max="3.141"
              min="0.01"
              unit="rad"
              widget="slider"&gt;
        &lt;name&gt;Initial angle&lt;/name&gt;
        &lt;value&gt;0.1&lt;/value&gt;
      &lt;/scalar&gt;</pre><p>The value of the parameter is adjustable via a
                  slider going from 0.01 to 3.141 and adjustable at near
                  0.001. It is there refered via the <code
                  class="code">label</code> <code
                  class="code">theta_0</code>.</p></td>
                </tr>
              </tbody>
            </table></div></li>

          <li><p>Gravity <span class="emphasis"><em>g</em></span> :</p><div
          class="informaltable"><table border="0">
              <colgroup>
                <col />

                <col />
              </colgroup>

              <tbody>
                <tr>
                  <td><div><img
                  src="images/xxe_param_g0.jpg"></img></div></td>

                  <td><pre class="programlisting">      &lt;scalar label="g0"
              unit="ms^-2"
              widget="entry"&gt;
        &lt;name&gt;Gravity&lt;/name&gt;
        &lt;value&gt;9.81&lt;/value&gt;
      &lt;/scalar&gt;</pre><p>The parameter value is entered via a text field
                  and its initial value is 9.81. It is there refered via the
                  <code class="code">label</code> <code
                  class="code">g0</code>.</p></td>
                </tr>
              </tbody>
            </table></div></li>
        </ul></div></li>

      <li><p><span class="bold"><strong>Resolution Parameters</strong></span>
      : The following lines describe each parameter which their entry is made
      in the window illustrated by the following figure :</p><div
      class="figure"><a id="id870529"></a><p
      class="title"><b>Figure&nbsp;3.3.&nbsp;Resolution parameters
      entry</b></p><div align="center" class="mediaobject"><img align="middle"
      alt="Saisie des paramètres de résolution"
      src="images/fen_pendule_param_resolution.jpg" /></div></div><div
      class="itemizedlist"><ul type="circle">
          <li><p>Upper limit <ns:math overflow="scroll"
              xmlns:ns="http://www.w3.org/1998/Math/MathML">
              <ns:semantics definitionURL="" encoding="">
                <ns:mrow>
                  <ns:msub>
                    <ns:mi>t</ns:mi>

                    <ns:mi>f</ns:mi>
                  </ns:msub>
                </ns:mrow>

                <ns:annotation encoding="MathType-MTEF" />
              </ns:semantics>
            </ns:math> of the interval discretization<mml:math
          overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML" />
          <mml:math overflow="scroll"
              xmlns:mml="http://www.w3.org/1998/Math/MathML">
              <mml:semantics definitionURL="" encoding="">
                <mml:mrow>
                  <mml:mrow>
                    <mml:mo>[</mml:mo>

                    <mml:mrow>
                      <mml:mn>0,</mml:mn>

                      <mml:mtext> </mml:mtext>

                      <mml:mtext> </mml:mtext>

                      <mml:msub>
                        <mml:mi>t</mml:mi>

                        <mml:mi>f</mml:mi>
                      </mml:msub>
                    </mml:mrow>

                    <mml:mo>]</mml:mo>
                  </mml:mrow>
                </mml:mrow>

                <mml:annotation encoding="MathType-MTEF" />
              </mml:semantics>
            </mml:math> used for the resolution of the differential equation
          giving the real pendulum movement (cf. <a href="#eq_pendule_reelle"
          title="Équation&nbsp;3.1.&nbsp;Equation réelle du mouvement du pendule">Equation&nbsp;3.1,
          «&nbsp;Real equation of the pendulum movement &nbsp;»</a>) :</p><div
          class="informaltable"><table border="0">
              <colgroup>
                <col />

                <col />
              </colgroup>

              <tbody>
                <tr>
                  <td><div><img
                  src="images/xxe_param_tf.jpg"></img></div></td>

                  <td><pre class="programlisting">      &lt;scalar label="tf"
              unit="s"
              widget="entry"&gt;
        &lt;name&gt;Final time&lt;/name&gt;
        &lt;value&gt;2&lt;/value&gt;
      &lt;/scalar&gt;</pre><p>The parameter value is entered via a text field
                  and its initial value is 2. It is there refered via the
                  <code class="code">label</code> <code
                  class="code">tf</code>.</p></td>
                </tr>
              </tbody>
            </table></div></li>
        </ul></div></li>
    </ul></div></div><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h3 class="title"><a
  id="id870717"></a>2.3.&nbsp;Simulation mathematicals models
  </h3></div></div></div><p>This section - which follows the tag <code
  class="code">&lt;/parameters&gt;</code> - allows to define the equations to
  be solved, the curves to be calculated, as well as the fields of values (1d
  or 2d) that some variables must take. These various definitions are framed
  by the following tags :</p><pre class="programlisting">  &lt;compute&gt;
  ...
  &lt;/compute&gt;</pre><p>As regards to our pendulum problem, the following
  elements are defined :</p><div class="itemizedlist"><ul type="disc">
      <li><p>Definition of the variable of integration and its interval of
      discretization <mml:math overflow="scroll"
          xmlns:mml="http://www.w3.org/1998/Math/MathML">
          <mml:semantics definitionURL="" encoding="">
            <mml:mrow>
              <mml:mrow>
                <mml:mo>[</mml:mo>

                <mml:mrow>
                  <mml:mn>0,</mml:mn>

                  <mml:mtext> </mml:mtext>

                  <mml:mtext> </mml:mtext>

                  <mml:msub>
                    <mml:mi>t</mml:mi>

                    <mml:mi>f</mml:mi>
                  </mml:msub>
                </mml:mrow>

                <mml:mo>]</mml:mo>
              </mml:mrow>
            </mml:mrow>

            <mml:annotation encoding="MathType-MTEF" />
          </mml:semantics>
        </mml:math> used for the resolution of the differential equation
      giving the real pendulum movement (cf. <a href="#eq_pendule_reelle"
      title="Équation&nbsp;3.1.&nbsp;Equation réelle du mouvement du pendule">Equation&nbsp;3.1,
      «&nbsp;Real equation of the pendulum movement&nbsp;»</a>) :</p><div
      class="informaltable"><table border="0">
          <colgroup>
            <col />

            <col />
          </colgroup>

          <tbody>
            <tr>
              <td><div><img
              src="images/xxe_intervalle_discretis.jpg"></img></div></td>

              <td><pre class="programlisting">    &lt;defdomain1d label="t"
                 unit="s"&gt;
      &lt;name&gt;Temps&lt;/name&gt;
      &lt;interval discretization="linear"
                steps="200"&gt;
        &lt;initialvalue&gt;0&lt;/initialvalue&gt;
        &lt;finalvalue&gt;tf&lt;/finalvalue&gt;
      &lt;/interval&gt;
    &lt;/defdomain1d&gt;</pre><p>It is indicated that the interval <mml:math
                  overflow="scroll"
                  xmlns:mml="http://www.w3.org/1998/Math/MathML">
                  <mml:semantics definitionURL="" encoding="">
                    <mml:mrow>
                      <mml:mrow>
                        <mml:mo>[</mml:mo>

                        <mml:mrow>
                          <mml:mn>0,</mml:mn>

                          <mml:mtext> </mml:mtext>

                          <mml:mtext> </mml:mtext>

                          <mml:msub>
                            <mml:mi>t</mml:mi>

                            <mml:mi>f</mml:mi>
                          </mml:msub>
                        </mml:mrow>

                        <mml:mo>]</mml:mo>
                      </mml:mrow>
                    </mml:mrow>

                    <mml:annotation encoding="MathType-MTEF" />
                  </mml:semantics>
                </mml:math> is cut out linearly in 200 steps. It is refered to
              the variable of integration and its field of variation via the
              <code class="code">label</code> <code
              class="code">t</code>.</p></td>
            </tr>
          </tbody>
        </table></div></li>

      <li><p>Definition of the element <code class="code">ode</code> (<span
          class="foreignphrase">
          <em class="foreignphrase">ordinary differential equation</em>
        </span>) grouping together the reference to the variable of
      integration and to its domain of variation, the definition of states
      <mml:math overflow="scroll"
          xmlns:mml="http://www.w3.org/1998/Math/MathML">
          <mml:semantics definitionURL="" encoding="">
            <mml:mi>θ</mml:mi>

            <mml:annotation encoding="MathType-MTEF" />
          </mml:semantics>
        </mml:math> and <mml:math overflow="scroll"
          xmlns:mml="http://www.w3.org/1998/Math/MathML">
          <mml:semantics definitionURL="" encoding="">
            <mml:mover accent="true">
              <mml:mi>θ</mml:mi>

              <mml:mo>˙</mml:mo>
            </mml:mover>

            <mml:annotation encoding="MathType-MTEF" />
          </mml:semantics>
        </mml:math>, as well as the list of the outputs, the only output being
      here the function giving the linearized solution<mml:math
          overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML">
          <mml:semantics definitionURL="" encoding="">
            <mml:mrow>
              <mml:mi>φ</mml:mi>

              <mml:mrow>
                <mml:mo>(</mml:mo>

                <mml:mi>t</mml:mi>

                <mml:mo>)</mml:mo>
              </mml:mrow>
            </mml:mrow>

            <mml:annotation encoding="MathType-MTEF" />
          </mml:semantics>
        </mml:math> of the value <mml:math overflow="scroll"
          xmlns:mml="http://www.w3.org/1998/Math/MathML">
          <mml:semantics definitionURL="" encoding="">
            <mml:mi>θ</mml:mi>

            <mml:annotation encoding="MathType-MTEF" />
          </mml:semantics>
        </mml:math> :</p><div class="informaltable"><table border="0">
          <colgroup>
            <col />

            <col />
          </colgroup>

          <tbody>
            <tr>
              <td><div><img
              src="images/xxe_structure_ode.jpg"></img></div></td>

              <td><pre class="programlisting">    &lt;ode label="pendulum"&gt;
      &lt;refdomain1d ref="t"/&gt;
      &lt;states&gt;
      ...
      &lt;/states&gt;
      &lt;outputs&gt;
      ...
      &lt;/outputs&gt;
    &lt;/ode&gt;</pre><p>Overall picture of the element <code
              class="code">ode</code> and the element <code
              class="code">refdomain1d</code> defining the reference to the
              variable of integration <code class="code">t</code>.</p></td>
            </tr>
          </tbody>
        </table></div><div class="itemizedlist"><ul type="circle">
          <li><p> <code class="code">states </code>element defining the states
          <mml:math overflow="scroll"
              xmlns:mml="http://www.w3.org/1998/Math/MathML">
              <mml:semantics definitionURL="" encoding="">
                <mml:mi>θ</mml:mi>

                <mml:annotation encoding="MathType-MTEF" />
              </mml:semantics>
            </mml:math> and <mml:math overflow="scroll"
              xmlns:mml="http://www.w3.org/1998/Math/MathML">
              <mml:semantics definitionURL="" encoding="">
                <mml:mover accent="true">
                  <mml:mi>θ</mml:mi>

                  <mml:mo>˙</mml:mo>
                </mml:mover>

                <mml:annotation encoding="MathType-MTEF" />
              </mml:semantics>
            </mml:math> :</p><div class="informaltable"><table border="0">
              <colgroup>
                <col />

                <col />
              </colgroup>

              <tbody>
                <tr>
                  <td><div><img
                  src="images/xxe_ode_states.jpg"></img></div></td>

                  <td><pre class="programlisting">      &lt;states&gt;
        &lt;state label="theta"
               unit="rad"&gt;
          &lt;name&gt;Real solution&lt;/name&gt;
          &lt;derivative&gt;theta_point&lt;/derivative&gt;
          &lt;initialcondition&gt;theta_0&lt;/initialcondition&gt;
        &lt;/state&gt;
        &lt;state label="theta_point"
               unit="rad"&gt;
          &lt;name&gt;angle derived&lt;/name&gt;
          &lt;derivative&gt;-g0/L*sin(theta)&lt;/derivative&gt;
          &lt;initialcondition&gt;0&lt;/initialcondition&gt;
        &lt;/state&gt;
      &lt;/states&gt;</pre><p>The states <code class="code">theta</code> and
                  <code class="code">theta_point</code> are defined, with for
                  each one of them the derived (function of the other states)
                  and the initial value taken for the initial value of the
                  variable of integration <code
                  class="code">t</code>.</p></td>
                </tr>
              </tbody>
            </table></div></li>

          <li><p> <code class="code">Outputs elements </code>defining as only
          output the function giving the linearized solution <mml:math
              overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML">
              <mml:semantics definitionURL="" encoding="">
                <mml:mrow>
                  <mml:mi>φ</mml:mi>

                  <mml:mrow>
                    <mml:mo>(</mml:mo>

                    <mml:mi>t</mml:mi>

                    <mml:mo>)</mml:mo>
                  </mml:mrow>
                </mml:mrow>

                <mml:annotation encoding="MathType-MTEF" />
              </mml:semantics>
            </mml:math> :</p><div class="informaltable"><table border="0">
              <colgroup>
                <col />

                <col />
              </colgroup>

              <tbody>
                <tr>
                  <td><div><img
                  src="images/xxe_ode_outputs.jpg"></img></div></td>

                  <td><pre class="programlisting">      &lt;outputs&gt;
        &lt;output label="thetalin"&gt;
          &lt;name&gt;Linearized solution&lt;/name&gt;
          &lt;value&gt;theta_0*cos(sqrt(g0/L)*t)&lt;/value&gt;
        &lt;/output&gt;
      &lt;/outputs&gt;</pre><p>The function of the linearized solution is
                  identified by the label <code
                  class="code">thetalin</code>.</p></td>
                </tr>
              </tbody>
            </table></div></li>
        </ul></div></li>
    </ul></div></div><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h3 class="title"><a
  id="id871365"></a>2.4.&nbsp;Simulation results display
  </h3></div></div></div><p>This section - which follows the tag <code
  class="code">&lt;/compute&gt;</code> - allows to define the various graphic
  windows, a set of system of axes for each one of it (windows which can then
  divide horizontally or vertically to contain them), as well as the curves
  which must be respectively displayed in each system of axis. These various
  definitions are framed by the following tags :</p><pre
  class="programlisting">  &lt;display&gt;
  ...
  &lt;/display&gt;</pre><p>In our case, a single window includes one system of
  Cartesian axis containing the curves of the real and the linearized
  solutions :</p><div class="itemizedlist"><ul type="disc">
      <li><p>Definition of the window :</p><div class="informaltable"><table
          border="0">
          <colgroup>
            <col />

            <col />
          </colgroup>

          <tbody>
            <tr>
              <td><div><img src="images/xxe_display.jpg"></img></div></td>

              <td><pre class="programlisting">    &lt;window&gt;
      &lt;title&gt;Comparison of both solutions&lt;/title&gt;
      &lt;axis2d xmax="tf" xmin="0"
              ymax="theta_0" ymin="-theta_0"&gt;
        &lt;drawcurve2d color="auto"
                     ref="theta" thickness="2" /&gt;
        &lt;drawcurve2d color="red"
                     ref="thetalin" thickness="2" /&gt;
      &lt;/axis2d&gt;
    &lt;/window&gt;</pre><p>The title of the window is indicated, which
              includes a system of Cartesian axis 2D, x varying from 0 to
              <ns:math overflow="scroll"
                  xmlns:ns="http://www.w3.org/1998/Math/MathML">
                  <ns:semantics definitionURL="" encoding="">
                    <ns:mrow>
                      <ns:msub>
                        <ns:mi>t</ns:mi>

                        <ns:mi>f</ns:mi>
                      </ns:msub>
                    </ns:mrow>

                    <ns:annotation encoding="MathType-MTEF" />
                  </ns:semantics>
                </ns:math> and y varying from <mml:math overflow="scroll"
              xmlns:mml="http://www.w3.org/1998/Math/MathML" /> <mml:math
                  overflow="scroll"
                  xmlns:mml="http://www.w3.org/1998/Math/MathML">
                  <mml:semantics definitionURL="" encoding="">
                    <mml:mrow>
                      <mml:mo>−</mml:mo>

                      <mml:msub>
                        <mml:mi>θ</mml:mi>

                        <mml:mn>0</mml:mn>
                      </mml:msub>
                    </mml:mrow>

                    <mml:annotation encoding="MathType-MTEF" />
                  </mml:semantics>
                </mml:math> to <mml:math overflow="scroll"
                  xmlns:mml="http://www.w3.org/1998/Math/MathML">
                  <mml:semantics definitionURL="" encoding="">
                    <mml:mrow>
                      <mml:msub>
                        <mml:mi>θ</mml:mi>

                        <mml:mn>0</mml:mn>
                      </mml:msub>
                    </mml:mrow>

                    <mml:annotation encoding="MathType-MTEF" />
                  </mml:semantics>
                </mml:math>. The system of axis defined contains the curve of
              the real solution (state <code class="code">theta</code>) and
              that of the linearized solution (output <code
              class="code">thetalin</code>).</p></td>
            </tr>
          </tbody>
        </table></div></li>
    </ul></div><p>The following curves thus are obtained :</p><div
  class="figure"><a id="id871575"></a><p
  class="title"><b>Figure&nbsp;3.4.&nbsp;Visualization of the pendulum
  simulation result </b></p><div class="screenshot"><div align="center"
  class="mediaobject"><img align="middle"
  alt="Visualisation du résultat de la simulation d'un pendule"
  src="images/fen_pendule_graph.jpg" /></div></div></div></div></div><div
  class="section" lang="fr" xml:lang="fr"><div class="titlepage"><div><div><h2
  class="title" style="clear: both"><a id="id871604"></a>3. Simulation
  enrichment &nbsp;example </h2></div></div></div><p>We are now going to
  develop the pendulum simulation to allow us to make vary <mml:math
      overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML">
      <mml:semantics definitionURL="" encoding="">
        <mml:mrow>
          <mml:msub>
            <mml:mi>θ</mml:mi>

            <mml:mn>0</mml:mn>
          </mml:msub>
        </mml:mrow>

        <mml:annotation encoding="MathType-MTEF" />
      </mml:semantics>
    </mml:math> by acting directly on the point <mml:math overflow="scroll"
      xmlns:mml="http://www.w3.org/1998/Math/MathML">
      <mml:semantics definitionURL="" encoding="">
        <mml:mrow>
          <mml:mo stretchy="false">(</mml:mo>

          <mml:mn>0,</mml:mn>

          <mml:mtext> </mml:mtext>

          <mml:msub>
            <mml:mi>θ</mml:mi>

            <mml:mn>0</mml:mn>
          </mml:msub>

          <mml:mo stretchy="false">)</mml:mo>
        </mml:mrow>

        <mml:annotation encoding="MathType-MTEF" />
      </mml:semantics>
    </mml:math> on the Scilab graph.</p><div class="section" lang="fr"
  xml:lang="fr"><div class="titlepage"><div><div><h3 class="title"><a
  id="id871705" />3.1.&nbsp;Creation of the <code class="code">point
  </code>element allowing to settle <mml:math overflow="scroll"
      xmlns:mml="http://www.w3.org/1998/Math/MathML">
      <mml:semantics definitionURL="" encoding="">
        <mml:mrow>
          <mml:msub>
            <mml:mi>θ</mml:mi>

            <mml:mn>0</mml:mn>
          </mml:msub>
        </mml:mrow>

        <mml:annotation encoding="MathType-MTEF" />
      </mml:semantics>
    </mml:math></h3></div></div></div><p>This element replaces the<code
  class="code"> scalar element</code> defining the parameter <code
  class="code">theta_0</code>. It is defined by its abscissa and its ordinate
  as well as the reference to a curve to which it is constrained to belong
  :</p><div class="informaltable"><table border="0">
      <colgroup>
        <col />

        <col />
      </colgroup>

      <tbody>
        <tr>
          <td><div><img src="images/xxe_point0.jpg"></img></div></td>

          <td><pre class="programlisting">  &lt;parameters&gt;
    &lt;section&gt;
      &lt;title&gt;Parameters of the pendulum&lt;/title&gt;
      ...
<span class="emphasis"><em>      &lt;point label="point0"
             widget="hidden"&gt;
        &lt;x1 label="zero"&gt;
          &lt;value&gt;0&lt;/value&gt;
        &lt;/x1&gt;
        &lt;x2 label="theta_0"&gt;
          &lt;value&gt;0.1&lt;/value&gt;
        &lt;/x2&gt;
        &lt;constraints&gt;
          &lt;curve ref="segment" /&gt;
        &lt;/constraints&gt;
      &lt;/point&gt;
</em></span>      ...</pre><p>The point is identified by the<code
          class="code"> label</code> <code class="code">point0</code>, its
          abscissa by the <code class="code">label</code> <code
          class="code">zero</code> (initial value 0), and its ordinate by the
          <code class="code">label</code> <code class="code">theta_0</code>
          (initial value 0.1) which is the parameter which we want to be able
          to adjust interactively. It does not here contain any interface of
          explicit seizure, but its graphic representation is manipulable (cf.
          <a href="#visu_point0"
          title="3.3.&nbsp;Ajout de la visualisation de point0">Section&nbsp;3.3,
          «&nbsp;Addition of the visualization of <code
          class="code">point0</code>&nbsp;»</a>).</p><p>The point is
          constrained to remain on the curve <code class="code">segment</code>
          that we now will define.</p></td>
        </tr>
      </tbody>
    </table></div></div><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h3 class="title"><a
  id="id871848"></a>3.2.&nbsp;Addition of the segment representing the forcing
  curve <code class="code">point0</code></h3></div></div></div><p>This element
  is added in the section <code class="code">compute</code> and is defined by
  the coordinates of its two extremities :</p><div
  class="informaltable"><table border="0">
      <colgroup>
        <col />

        <col />
      </colgroup>

      <tbody>
        <tr>
          <td><div><img src="images/xxe_polyline.jpg"></img></div></td>

          <td><pre class="programlisting">  &lt;compute&gt;
    ...
<span class="emphasis"><em>    &lt;polyline label="segment"&gt;
      &lt;vertex x1="0" x2="0"&gt;&lt;/vertex&gt;
      &lt;vertex x1="0" x2="3.141"&gt;&lt;/vertex&gt;
    &lt;/polyline&gt;
</em></span>    ...</pre><p>The element <code class="code">polyline</code> is
          a multiple-line curve defined by all the points (elements <code
          class="code">vertex</code>) of the segments composing it.</p>We
          define here a single segment (named <code
          class="code">segment</code>) which the ordinates of the points
          constituent it, represent the possible values for the parameter
          <code class="code">theta_0</code>. For more information about the
          <code class="code">segment</code> element, refer to the document <em
          class="citetitle"> XMLlab-1.4</em> <i>Software Reference Manual</i>,
          in § <em class="citetitle">Tag <code
          class="code">polyline</code></em> of the chapter referring the
          elements taking part in the simulation description.</td>
        </tr>
      </tbody>
    </table></div></div><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h3 class="title"><a
  id="visu_point0"></a>3.3.&nbsp;Addition of the <code class="code">point0
  <tt>visualization</tt> </code></h3></div></div></div><p>Consists of the
  addition of a <code class="code">drawpoints element to the system of
  existing axis </code> :</p><div class="informaltable"><table border="0">
      <colgroup>
        <col />

        <col />
      </colgroup>

      <tbody>
        <tr>
          <td><div><img src="images/xxe_drawpoints.jpg"></img></div></td>

          <td><pre class="programlisting">  &lt;display&gt;
    &lt;window ...&gt;
      &lt;title&gt;Comparison of both solutions&lt;/title&gt;
      &lt;axis2d ...&gt;
        &lt;drawcurve2d ...
                     ref="theta" ... /&gt;
        &lt;drawcurve2d ...
                     ref="thetalin" ... /&gt;
        <span class="emphasis"><em>&lt;drawpoints ref="point0" /&gt;</em></span>
      &lt;/axis2d&gt;
    &lt;/window&gt;
  &lt;/display&gt;</pre><p>The <code class="code">drawpoints</code> element is
          defined by the reference to the <code class="code">point</code>
          element which it represents.</p></td>
        </tr>
      </tbody>
    </table></div></div><div class="section" lang="fr" xml:lang="fr"><div
  class="titlepage"><div><div><h3 class="title"><a
  id="id872033"></a>3.4.&nbsp;Simulation new version
  test</h3></div></div></div><p>The following figure illustrates the use of
  the point <code class="code">point0</code> added to modify <mml:math
      overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML">
      <mml:semantics definitionURL="" encoding="">
        <mml:mrow>
          <mml:msub>
            <mml:mi>θ</mml:mi>

            <mml:mn>0</mml:mn>
          </mml:msub>
        </mml:mrow>

        <mml:annotation encoding="MathType-MTEF" />
      </mml:semantics>
    </mml:math> :</p><div class="figure"><a id="id872082"></a><p
  class="title"><b>Figure&nbsp;3.5.&nbsp;Interactive modification of the
  <mml:math overflow="scroll" xmlns:mml="http://www.w3.org/1998/Math/MathML">
      <mml:semantics definitionURL="" encoding="">
        <mml:mrow>
          <mml:msub>
            <mml:mi>θ</mml:mi>

            <mml:mn>0 parameter</mml:mn>
          </mml:msub>
        </mml:mrow>

        <mml:annotation encoding="MathType-MTEF" />
      </mml:semantics>
    </mml:math></b></p><div class="screenshot"><div align="center"
  class="mediaobject"><img align="middle"
  alt="Modification interactive du paramètre θ 0"
  src="images/fen_pendule_point0.jpg" /></div></div></div><p>The point is
  represented by a cross situated in the top of the Y axis. To modify the
  parameter <code class="code">theta_0</code>, click on the cross, the
  coordinates of <code class="code">point0</code> (whose the ordinate is <code
  class="code">theta_0</code>) then displays. Move the cursor above or below
  the cross, as it is a question of increasing or decreasing <code
  class="code">theta_0</code> (curves are real time recalculated). Once the
  value wished obtained, click again the cross to fix the value of <code
  class="code">theta_0</code>.</p></div></div></div></div></body>
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