<simulation>
  
<header>
    
<title lang="english">System of differential equations</title>
    
<title>Système d'équations différentielles</title>
    
<title lang="spanish">Sistema de ecuaciones diferenciales</title>
    
<author>Stéphane Mottelet, Guillaume Barbaud</author>
    
<keywords>simulation,scilab,xml</keywords>
    
<keywords lang="spanish">Simulación, XML, Scilab</keywords>
  
</header>
  
<notes>
    
<p>Une simulation très simple montrant la solution d'un système de deux équation différentielle linéaire
à coefficients constants.
    
</p>
  
</notes>
  
<notes lang="english">
    
<p>A very simple example showing the solution of  system of two linear ordinary differential 
    equation with constant coefficients.
    
</p>
  
</notes>
  
<notes lang="german">
    
<p />
  
</notes>
  
<notes lang="spanish">
    
<p>Una simulación muy sencilla que muestra la solución de un sistema de dos ecuaciones diferenciales lineales con coeficientes constantes..</p>
  
</notes>
  
<parameters>
    
<section>
      
<title lang="english">Parameters of the equation</title>
      
<title>Paramètres de l'équation</title>
      
<title lang="spanish">Parametros de la ecuación</title>
      
<database label="matriceA" editable="yes">
        
<matrix label="a" cols="2" rows="2">
          
<name>Matrice du système</name>
          
<name lang="english">Matrix of the system</name>
          
<name lang="spanish">Matriz del sistema</name>
          
<row>
            
<value>1 1</value>
          
</row>
          
<row>
            
<value>0 1</value>
          
</row>
        
</matrix>
        
<record>
          
<name lang="english">Stable system</name>
          
<name lang="french">Système stable</name>
          
<name lang="spanish">Sistema estable</name>
          
<matrix-value ref="a">
            
<row>
              
<value>-1 1</value>
            
</row>
            
<row>
              
<value>0 -1</value>
            
</row>
          
</matrix-value>
        
</record>
        
<record>
          
<name lang="french">Oscillateur</name>
          
<name lang="english">Oscillator</name>
          
<name lang="spanish">Oscilador</name>
          
<matrix-value ref="a">
            
<row>
              
<value>0 1</value>
            
</row>
            
<row>
              
<value>-1 0</value>
            
</row>
          
</matrix-value>
        
</record>
        
<record>
          
<name lang="french">Système instable</name>
          
<name lang="english">Unstable system</name>
          
<name lang="spanish">Sistema inestable</name>
          
<matrix-value ref="a">
            
<row>
              
<value>1 1</value>
            
</row>
            
<row>
              
<value>0 1</value>
            
</row>
          
</matrix-value>
        
</record>
        
<record>
          
<name lang="french">prout</name>
          
<matrix-value ref="a">
            
<row>
              
<value>0 0</value>
            
</row>
            
<row>
              
<value>0 -1</value>
            
</row>
          
</matrix-value>
        
</record>
      
</database>
      
<subsection>
        
<matrix label="xzero" cols="1" rows="2">
          
<name>Condition initiale</name>
          
<name>Initial condition</name>
          
<name lang="english">x0</name>
          
<name lang="spanish">Condiciones iníciales</name>
          
<col>
            
<value>1 1</value>
          
</col>
        
</matrix>
        
<scalar label="tmax" min="1" max="20" increment="1">
          
<name>Temps final</name>
          
<name lang="english">Final time</name>
          
<name lang="spanish">Tiempo final</name>
          
<value>10</value>
        
</scalar>
      
</subsection>
    
</section>
  
</parameters>
  
<compute>
    
<defdomain1d label="t">
      
<name lang="english">Time</name>
      
<name>Temps</name>
      
<name lang="spanish">Tiempo</name>
      
<interval steps="256">
        
<initialvalue>0</initialvalue>
        
<finalvalue>tmax</finalvalue>
      
</interval>
    
</defdomain1d>
    
<ode label="ode1">
      
<refdomain1d ref="t" />
      
<states>
        
<state label="x" size="2">
          
<name>x</name>
          
<name lang="english">x</name>
          
<name lang="spanish">X</name>
          
<derivative>a*x</derivative>
          
<initialcondition>xzero</initialcondition>
        
</state>
      
</states>
      
<outputs>
        
<output label="x1">
          
<name>x1(t)</name>
          
<name lang="english">x1(t)</name>
          
<name lang="spanish">x1(t)</name>
          
<value>x(:,1)</value>
        
</output>
        
<output label="x2">
          
<name>x2(t)</name>
          
<name lang="english">x2(t)</name>
          
<name lang="spanish">x2(t)</name>
          
<value>x(:,2)</value>
        
</output>
      
</outputs>
    
</ode>
  
</compute>
  
<graphs />
  
<display>
    
<window>
      
<axis2d xmin="0" xmax="tmax" ymin="min(x)" ymax="max(x)">
        
<drawcurve2d ref="x1" />
        
<drawcurve2d ref="x2" />
      
</axis2d>
    
</window>
  
</display>
</simulation>