Compute derivative states.
values = fmiGetDerivatives(instance)
tlist, an instance of a model.
real vector, derivative states.
fmiGetDerivatives is the function which compute derivatives states at the current time instant and for the current states.
The ordering of the elements of the derivative vector is identical to the ordering of the state vector
(e.g. values[2] is the derivative of values[2] of fmiGetContinuousStates).