Multiple time steps in one single Model!

[majidshafieejood]

Hi,
I am working on an integrated water management model using VENSIM!
the model has two main sectors, one is called rainfall-runoff modelling sector (with time steps in day) and the other is called water resources operating sector (with time steps in month).
I want to know whether it is possible to define two different time steps in one unite model?

[tomfid]

Hi - The short answer is no. It's possible to have a variable time step, which can sometimes be used for distinct purposes (e.g., to model a dry season and a wet season differently). It's also possible to coordinate two models with different time steps using the .dll, with some kind of coordinating application (Java). Usually the easiest solution by far is to simply waste clock cycles and run your water resources operating sector daily, even though it only needs to execute monthly. This is generally not a problem unless your model is very large. - Tom

[majidshafieejood]

I am sorry but I have another question.
I am calling VENSIM from c++ using vensim dll.
I have written a Genetic Algorithm in c++ and it calls VENSIM.
There was no problem until yesterday. But from yesterday what ever I do after 139 generations that 139*60 times calling VENSIM, an STOP MESSAGE FROM VENSIM occurs which says: problem in performing simulation , and when I check in Microsoft Visual Studio the error in output debugging is "First-chance exception at 0x75d3d36f in Majid.exe: 0x8007000E: Not enough storage is available to complete this operation".
I don't know what can be the reason. I have 10 GB free in the drive c and more than 40GB free in the drive in which the VENSIM model and c++ code exist.
Please help me, I really am in a bad situation
Thanks

[Administrator]

Can you let us know your Vensim serial number please (click Help->About Vensim)?

You will need to look at the Vensim results file to find out what happened. "Problem performing simulation" usually means a division by zero.

[majidshafieejood]

Thanks,
But just now the problem was solved!
The values of the timestep in excel (Vensim reads from Excel) were stores as text. that error : not enough space was because of this
Anyway thanks