create DAE with Input

Hello,

I want to solve a DAE problem with the ODE solvers. I try to create my system like shown here:

http://de.mathworks.com/help/symbolic/solve-dae-system-using-matlab-ode-solvers.html

(ode15i example)

My Problem, I have Inputs for my system, which are actually functions. They get passed t and return a value out of an array.

How do i declare these functions? When im at the point where i want to use "daeFunction" i get an error "Found the symbolic object ... in the DAES. Only variables and declared parameters may be symbolic."

Can anyone help me?

Thanks

[Torsten]

Create a time array and an array of input values for the dae system at these times. Then use interp1 to interpolate your input array to the times requested by the solver in the daeFunction.

Best wishes

Torsten.

[Kai]

So when i got a function u1(t) before, i replace it with interp1(...,...,t)?

Thanks!

[Torsten]

If you have functions which enter the DAE system, why don't you just call them in the ODE routine for the time the ODE integrator requires and use the values returned as input for your ODE system ?

Best wishes

Torsten.