Ventana software support forum

Thank you very much, Bob - your hint pointed in the right direction: It made me check the function signatures of the library again, and - I have no idea why, maybe someone updated Vensim - they have changed. Previously, the function vensim_command e.g. needed the matlab type VoidPtr as input argumen...

No, Matlab has not been upgraded.

I can't imagine why the strings being passed would not be valid any more, since I did not change the subroutine I use to load models in any way. But I'll take a look at that, thank you.

I'd still appreciate other ideas, though... this is really important.

There is a file named 'vensimdll.err'. Is that the same as vendll.err?
This file contains the following:

Vensim® DLL(Full) version 5.9e error log starting Wed Nov 17 12:27:15 2010
ERROR: Class °‡ without command.

I am back with a new problem. As you remeber, I managed to control Vensim via Matlab on a WinXP computer. Meanwhile, my intership came to an end, so I didn't work with Vensim for some time. Now I tried again to call Vensim from Matlab on the same computer - and it does not work anymore. I simply can...

I've never had these warning messages before. Have you checked which functions are contained in the library you loaded? You can do so with "libfunctionsview('vendll32')". My vendll32 does contain 'VensimCGetSubstring', but not vensim_shutdown. That one isn't even mentioned in the manual, s...

I discovered something new: The model reads some data from excel files. I found out that I have to close all excel files before starting a new simulation from matlab, because otherwise the freezing happens. That's why it worked right after booting the system, because then the excel files were closed...

If you open the windows task manager you may be able to track down what process is consuming the memory. The process consuming up to 99% of CPU is a process called "system idle process". (I don't know if that is the exact translation, in german it is "Leerlaufprozess".) What doe...

Meanwhile, I'm not getting the "model cannot be simulated"-error anymore. The situation is: Directly after booting the computer calling vensim functions works just finde. But after a short time, everything slows down and it takes minutes just to retrieve one value. At some time matlab simp...

Yes, I am sure. It is the right model and all needed excel files are in the same directory. I should add that once or twice I was actually able to run a simulation. Other times I get the mentioned error. And sometimes (quite often) matlab simply freezes and does nothing, in which case I have to manu...

I opened a new thread since the other one meanwhile covers different subjects. (For those who read my questions according Win7: I'm working with the WinXP-Computer again right now.) Loading models into matlab, setting and getting variables does work in general. However, when I try to work with a cer...

The model is, and always was, located in Users\Username\Documents\MATLAB\Vensim.

Is there any attribute of the model I can check which could cause the failure? It is not write-protected.

[Edited on 9-3-2010 by arraywanted]

arraywanted - if LOADMODEL returns 0 it should put up an error dialog - if you set BEQUIET take that setting away. Otherwise see if you can find vendll.err as that may hold a clue. No, there is no dialog showing, LOADMODEL just returns 0 and that's it. I called venim_be_quiet(0) to be sure - that's...

I don't know if that was clear: I'm not getting a matlab error this time, vensim_command(SPECIAL>LOADMODEL...) just always returns 0.

By the way, the windows 7-computer has also a 64bit operating system. Connection with my problem possible?

If I try other functions like vensim_check_status or start_simulation, it works. But I just can't load a model.

Please, can anyone help me? I'm getting a bit desperate.

No, version 5.9e.

No ideas? I am still stuck here and would be really grateful!

I also tried moving the files to another directory, but that didn't help.

I really have no clue what the problem is... anyone?

I moved all files necessary to the MATLAB folder in Username\Documents, to be on the safe side. Doesn't work still. The vensim.err file contains errors, which I don't really understand: The model which I tried to load has been simulated several times from vensim before and the runs were saved under,...

I have a new problem: I tried to call vensim from matlab on another computer, namely my notebook with win7 as operating system. Loading the library does work, but I cannot load any model although I use the exact same commands as on the other computer (which has win xp). Do you have any idea how to m...

Thank you, it works with a loop. I haven't tried the option with the cin-file, but I probably will because with loops it is quite ugly.

Next question right away:
Is there any way to display the graph of a variable after a simulation when calling the vensim dll? Or is it impossible from the outside?

Well of course, if you haven't managed to load the library, you won't be able to load a model. You will have to fix that first. Unfortunately, I don't understand the error message you posted in the other thread. Maybe one of the others does? I have a question myself: I want to set the value of a sub...

Did you solve the problem posted in the other thread? Here is a subroutine I wrote to load a model: ----------------------- function loadModel(modelName) % Loads a Vensim model specified by the string ModelName % The vendll32 library must have been loaded str=['SPECIAL>LOADMODEL|',ModelName,'.vpm'];...

I think your header file (matrix.h) is the wrong one. You got that one from the example with the libmx library on the mathworks page, didn't you? That won't work for vensim. The correct header file is vendll.h, it can be found in the same folder as vendll32.lib. Now, if you navigate to that folder a...

I finally found out how to pass string arguments to vensim. You have to use the libpointer function in matlab.

All of you, thank you very much for your help. I may have more questions later, though...

vensim_command("SPECIAL>LOADMODEL|modelname.vpm")

Would that be correct, then?