I misstated the call to ODE in the original post: was posted as: y=ode(y0,t0,t,list(rdv,a,b,c)); should be: y=ode(y0,t0,t,rdv); apologies - marko -- Sent from: http://mailinglists.scilab.org/Scilab-users-Mailing-Lists-Archives-f2602246.html