Neil The desired help came very fast, thanks!. I have a systems that receives very complex inputs that make use of crazy functions such as Mod and Quotient. I did not know there are name differences such quotient and div between mathematica and SystemModeler. Actually, your nonsensical examples make a lot of sense and really helped.

Thanks again.

Regards

Jesús

Thanks

SystemModeler has help me a lot in many ways but going from doing simulation in Mathematica to simulating in SystemModer has not been always easy. Mathematic has a function for virtually everything one requires in simulating dynamical systems and I am skeptical the catalog Modelica functions is as long. In this case, for example, I noticed that there are differences between Quotient[] and div(), Quotient gives the integer quotient of m and n and div seem to be a classical division. Am I right?

Regards

Jesus

Jesus,

It works well. By saying you want to "import" them into SystemModeler I assume you mean from Mathematica. Here is a simple example from the documentation for taking an equation and creating a model:

mmodel = WSMCreateModel[
   "DiffEq2", {x''[t] + 1/10 x'[t] + Sin[x[t]] == 1/2 Cos[t],  x[0] == 0, x'[0] == 0}, t];
WSMModelData[mmodel, "ModelicaText"]

This produces a simple Modelica model:

model DiffEq2
  Real x;
  Real derx129;
initial equation
  x = 0;
  der(x) = 0;
equation
  sin(x) + 1 / 10 * der(x) + der(derx129) = 1 / 2 * cos(time);
  derx129 = der(x);
end DiffEq2;

If you add a (in this case, nonsensical) Mod and Quotient you get:

mmodel = WSMCreateModel[
   "DiffEq4", {x''[t] + 1/10 x'[t] + Mod[Sin[x[t]], 5] == 
     Quotient[1/2 Cos[t], 2], x[0] == 0, x'[0] == 0}, t];
WSMModelData[mmodel, "ModelicaText"]

you get the correct modelica code:

model DiffEq4
  Real x;
  Real derx131;
initial equation
  x = 0;
  der(x) = 0;
equation
  mod(sin(x), 5) + 1 / 10 * der(x) + der(derx131) = div(1 / 2 * cos(time), 2);
  derx131 = der(x);
end DiffEq4;

Note that the modelica function for Mod is mod() and the modelica function for Quotient is div(). You can see all the modelica functions in the modelica manual in PDF here

If on the other hand you meant "how do you use these functions in a modelica model?", the answer is to go to text mode and type mod() and div() directly. Modelica has a very rich and complete language so you can do just about anything,,,

You can also create a model in WSM, query the equations from Mathematica, alter the equations to add your nonlinear parts and send it back to WSM as a new nonlinear model.

I hope this helps.

Regards,

Neil