<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
  <meta content="text/html; charset=ISO-8859-1"
 http-equiv="Content-Type">
  <title></title>
</head>
<body bgcolor="#ffffff" text="#000000">
Le 19/09/2011 19:37, Reinaldo a écrit :
<blockquote
 cite="mid:1316453825.46603.YahooMailNeo@web45514.mail.sp1.yahoo.com"
 type="cite">
  <div
 style="color: rgb(0, 0, 0); background-color: rgb(255, 255, 255); font-family: arial,helvetica,sans-serif; font-size: 10pt;">
  <div><span>I try to understand the help of <em>syslin</em> function,
but it is hard ! </span></div>
  <div><span></span> </div>
  <div><span>The description is:</span></div>
  <div><span></span> </div>
  <div><span> </span></div>
  <div class="refsection">
  <div class="para"> State-space representation: </div>
  <div class="programlisting">
  <table width="100%" border="0">
    <tbody>
      <tr>
        <td width="98%">
        <pre class="scilabcode"><span class="scilabid">sl</span><span
 class="scilaboperator">=</span><span class="scilabmacro">syslin</span><span
 class="scilabopenclose">(</span><span class="scilabid">dom</span><span
 class="scilabdefault">,</span><span class="scilabid">A</span><span
 class="scilabdefault">,</span><span class="scilabid">B</span><span
 class="scilabdefault">,</span><span class="scilabid">C</span> <span
 class="scilabopenclose">[</span><span class="scilabdefault">,</span><span
 class="scilabid">D</span> <span class="scilabopenclose">[</span><span
 class="scilabdefault">,</span><span class="scilabid">x0</span><span
 class="scilabopenclose">]</span> <span class="scilabopenclose">])<var
 id="yui-ie-cursor"></var></span></pre>
        </td>
        <td valign="top"> <a moz-do-not-send="true"
 href="scilab://scilab.execexample/"><img moz-do-not-send="true"
 src="http://us.mg3.mail.yahoo.com/neo/ScilabExecute.png" border="0"> </a>
        </td>
        <td valign="top"> <a moz-do-not-send="true"
 href="scilab://scilab.editexample/"><img moz-do-not-send="true"
 src="http://us.mg3.mail.yahoo.com/neo/ScilabEdit.png" border="0"> </a>
        </td>
        <td> <br>
        </td>
      </tr>
    </tbody>
  </table>
  </div>
  <div class="para"> represents the system :
     </div>
  <div class="para"> </div>
  <div class="para">s.x  = A.x + B.u</div>
  <div class="para">y = C.x + D.u</div>
  <div class="para">x(0) = x0<var id="yui-ie-cursor"></var></div>
  </div>
  <div> </div>
  <div>I don't know how to correspond those [ [ ] ] to that linear
system. </div>
  </div>
</blockquote>
<br>
In this context, this means that D (and even x0) are optionnal. They
are not compulsory.<br>
That is to say, you can call <br>
<pre class="scilabcode"><span class="scilabid">sl</span><span
 class="scilaboperator">=</span><span class="scilabmacro">syslin</span><span
 class="scilabopenclose">(</span><span class="scilabid">dom</span><span
 class="scilabdefault">,</span><span class="scilabid">A</span><span
 class="scilabdefault">,</span><span class="scilabid">B</span><span
 class="scilabdefault">,</span><span class="scilabid">C</span><span
 class="scilabopenclose"></span><span class="scilabdefault">,</span><span
 class="scilabid">D</span>)<span class="scilabopenclose"></span><span
 class="scilabdefault"></span><span class="scilabid"></span><span
 class="scilabopenclose"></span><span class="scilabopenclose">)</span></pre>
or even<br>
<pre class="scilabcode"><span class="scilabid">sl</span><span
 class="scilaboperator">=</span><span class="scilabmacro">syslin</span><span
 class="scilabopenclose">(</span><span class="scilabid">dom</span><span
 class="scilabdefault">,</span><span class="scilabid">A</span><span
 class="scilabdefault">,</span><span class="scilabid">B</span><span
 class="scilabdefault">,</span><span class="scilabid">C</span><span
 class="scilabopenclose"></span><span class="scilabdefault">,</span><span
 class="scilabid">D</span><span class="scilabopenclose"></span><span
 class="scilabdefault">,</span><span class="scilabid">x0</span><span
 class="scilabopenclose"></span><span class="scilabopenclose">)</span></pre>
but not<br>
<pre class="scilabcode"><span class="scilabid">sl</span><span
 class="scilaboperator">=</span><span class="scilabmacro">syslin</span><span
 class="scilabopenclose">(</span><span class="scilabid">dom</span><span
 class="scilabdefault">,</span><span class="scilabid">A</span><span
 class="scilabdefault">,</span><span class="scilabid">B</span><span
 class="scilabdefault">,</span><span class="scilabid">C</span><span
 class="scilabopenclose"></span><span class="scilabdefault"></span><span
 class="scilabid"></span><span class="scilabopenclose"></span><span
 class="scilabdefault">,</span><span class="scilabid">x0</span><span
 class="scilabopenclose"></span><span class="scilabopenclose">)
</span></pre>
<span class="scilabopenclose">because here [[] ] are nested <br>
(to allow also this last synopsis, the notation</span><span
 class="scilabopenclose"> would have been </span>instead<br>
<pre><span class="scilabid">sl</span><span class="scilaboperator">=</span><span
 class="scilabmacro">syslin</span><span class="scilabopenclose">(</span><span
 class="scilabid">dom</span><span class="scilabdefault">,</span><span
 class="scilabid">A</span><span class="scilabdefault">,</span><span
 class="scilabid">B</span><span class="scilabdefault">,</span><span
 class="scilabid">C</span> <span class="scilabopenclose">[</span><span
 class="scilabdefault">,</span><span class="scilabid">D]</span><span
 class="scilabopenclose">[</span><span class="scilabdefault">,</span><span
 class="scilabid">x0</span><span class="scilabopenclose">]</span><span
 class="scilabopenclose">)</span></pre>
This is a general and common convention<br>
<br>
HTH<br>
Regards<br>
Samuel<br>
<br>
</body>
</html>