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/* Copyright Inria/Enpc */
/*********************************************
* external fonction for ode
* input variables n, t, y
* n = dimension of state vector y
* t = time
* y = state variable
* output variable = ydot
* ================================
* external routine must
* load ydot[0] with d/dt ( y(1)(t) )
* ydot[1] with d/dt ( y(2)(t) )
* ...
* i.e. ydot vector of derivative of state y
* ================================
* With dynamic link:
* link('ext10c.o','ext10c','C')
* ================================
* passing a parameter to ext6 routine by a list:
* -->param=[0.04,10000,3d+7];
* -->y=ode([1;0;0],0,[0.4,4],list('ext10c',param))
* param is retrieved in ext6 by:
* param[0]=y[ *n ] , param[1]=y[ *n + 1] etc
* with this calling sequence y is a n+np vector
* where np=dimension of scilab variable param
*********************************************/
int ext10c(n, t, y, ydot)
int *n;
double *t, *y, *ydot;
{
static double param[3];
param[0] = y[*n + 0];
param[1] = y[*n + 1];
param[2] = y[*n + 2];
ydot[0] = -param[0] * y[0] + param[1] * y[1] * y[2];
ydot[2] = param[2] * y[1] * y[1];
ydot[1] = -ydot[0] - ydot[2];
return(0);
}
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