Thanks for the tips. One more question that I'm fairly embarrassed to ask... how do you write and run scripts? I can get things going from OMShell but obviously I'd rather write the script once then run it later. Do I just write the script in any old text editor, then run it using runScript(filepath)? Or is there an integrated script writing environment?

It looks like OMNotebook is what I need but I haven't gotten super deep into it yet and I'd rather avoid a false start if possible.

(I'm coming from Scilab, where there's a built-in editor with syntax checking, highlighting, that kind of thing, so I'm wondering what my best option is here in OpenModelica).

Thanks again all, sorry for the newb questions!

I'm quite new to Modelica here so hopefully this is an easy one. I have a simulation created in OMEdit that works well when I simulate it. I'd like to move on to simulating this model with a variety of different inputs while logging data automatically.

For example, I have a sine wave input force going into the system. I'd like to see the system's response to 10-100 Hz input sine waves in 10 Hz increments. Right now I can manually change the value, run the sim, then export the CSV to my analysis program, but that seems quite inefficient- I'd rather update my model, then hit "go" and get results for 10 different frequencies, or 10 different phases, or whatever. Just a constant input parameter evenly spaced over a predetermined range.

I've been looking at OMOptim but I don't see a way to specify input values, and I don't see a way to run it without trying to optimize anything. The results I'm looking at have to be post-processed and there aren't really good ways to define them as "optimized" anyway; I just need to know some frequency response information.

Is there a way within OMEdit, OMOptim, or the OM Shell to do something like this? I haven't done any scripting with Modelica yet, but if that's the way to go I'd be happy to learn.

Thanks for the help.

I made some progress on this one- apparently the third prismatic joint was giving it issues. Replacing the far right prismatic joint with just a 3D spring seemed to fix things for now, but I'll see how it goes when I have to start actually using the model.

If anyone can offer insight on why I can't have the third prismatic joint in there I'd greatly appreciate it.

In OMEdit, right click on "ModelicaServices" then "Unload". Next, go to your OpenModelica folder, then lib/omlibrary/ModelicaServices 3.2.1 modelica3d and load the "package.mo" file found there. You'll get a new ModelicaServices package loaded into OMEdit.

Expand that package, go to Modelica3d, then drag the Controller element onto your diagram. You'll have to do this package unload/reload every time unless you change your default settings, it doesn't stick by itself.

Also before running your simulation, run dbus-server.py in \lib\omlibrary-modelica3d\osg-gtk. You'll need Python and some other components as well, it's documented in the user guide for Modelica3D.

I'm trying to simulate a system similar to this one:

http://scienceworld.wolfram.com/physics … asses.html

I can simulate it just fine using 1-D translational elements, but I'm trying to do it in 3D with the multibody tools and I'm having trouble getting it to run. I eventually need to have a 3D system built with these components but this is my first time using Modelica so I'm trying to get a very simplified system to run, hence using 3D tools to solve a 1D problem- eventually it will be 3D.

I have attached my (primitive) stab at making this system.

SingleStrut5.mo

Right now it gives me an error that I have mismatched equations and variables, and I suspect it has something to do with my initial conditions but I'm stumped. Any help would be much appreciated!

Edit: Tried a couple more things. I replaced the frame translation element with a BodyCylinder of the same length, and now I have matched equations and variables. Unfortunately, trying to run it gives me "An independent subset of the model has imbalanced number of equations (1) and variables (0). variables:equations: 1 : 0.0 = 0.0".