Model working directory

[phuoc]

Hello,

As I understand that the current working directory of the simulation is the same as the model directory. I try to load data in a parent directory in external C++ functions, forexample "..\data\file1.dat". My question is whether the reference to the parent directory of the current model, i.e. "..\", valid in external functions. It seems that I can do this in previous Vensim version but not the current version 6.0.

Thanks

[etam]

I'd suggest to use the absolute path of the current directory. As I remember you can add the relative to that as well (e.g. D:\MyProject\Model\..\data\file1.dat)
Check the vensim_get_info function in the DSS doc.

Code: Select all

char curr_dir[MAX_LEN];
(*VENGV->get_info)(4, curr_dir, MAX_LEN);

However, I don't know if the get_info has proper results in version 6.0. I have only a 5.11 license, in that it does.

[tomfid]

We haven't changed anything about external functions in 6.0 so whatever worked before should still work - if not, an example might help us diagnose the problem.

[phuoc]

Hi etam and tomfid,

I am sorry for the late response. I can use the relative path in the external dll when I run the model directly in Vensim. However I cannot read or write to files when I run the same model under Vensim dll. Please find attached my example, adapting from Vensim's samples. The WORLDAPP.vmf model uses the external PSUM function in VENEXT.C. In the PSUM function I print out the current directory to a file. This works when I run it directly. Then I publish the model to WORLDAPP.vpm and run it through the Vensim dll sample 'C:\Documents and Settings\All Users\Vensim\dll\csharp\VensimDemo'. This time it doesn't print the current directory to a file but it does produce the output current.vdf. Does this means that Vensim dll ignore my code to print out to a file, both absolute and relative paths?

Thanks for your quick responds

[Administrator]

Have you loaded the external function library?

I'm writing on a phone, but you need to specify the external function lib in an ini file, and then call the loadini venapp command to load it.

[phuoc]

That's my fault, I forgot to load the external dll. I fixed it and it works now.

Many thanks