Search found 9 matches
- Wed Nov 14, 2018 8:38 pm
- Forum: Vensim
- Topic: Changing the order of calculations
- Replies: 10
- Views: 5449
Re: Changing the order of calculations
Thanks. I do think it is a gaming issue. I'm starting to better understand now and made some progress on improving the order of calculations by changing the order in which the gaming variables are defined. You were right in that it is not a Vensim issue - It was a modelling mistake made by me in set...
- Wed Nov 14, 2018 7:55 pm
- Forum: Vensim
- Topic: Changing the order of calculations
- Replies: 10
- Views: 5449
Re: Changing the order of calculations
I wonder if I add some more inputs to what I want calculated last, just as a + 0*variable, whether it would trick Vensim into using the order I want... I'm now just trying to change the order of calculations for the Aux. variables (gate position is no longer a stock).
- Wed Nov 14, 2018 7:39 pm
- Forum: Vensim
- Topic: Changing the order of calculations
- Replies: 10
- Views: 5449
Re: Changing the order of calculations
It's hard to show an example of what the model does because it's implemented and run using VenPy which substitutes different values in for the gaming variables. These gaming variables are a key part of how the model functions (and perhaps have something to do with the calculation order problems..) I...
- Wed Nov 14, 2018 12:06 am
- Forum: Vensim
- Topic: Changing the order of calculations
- Replies: 10
- Views: 5449
Re: Changing the order of calculations
Doing that actually caused an additional day delay somehow.. No idea why that is happening given that I haven't added delays anywhere. Perhaps it has to do with my adding a game variable to hold the gate position to be used at the next time step - maybe the game variables are returned at a strange t...
- Tue Nov 13, 2018 8:32 pm
- Forum: Vensim
- Topic: Changing the order of calculations
- Replies: 10
- Views: 5449
Re: Changing the order of calculations
I'm running a daily time step - there are no delay functions in the model at all. I previously had an hourly time step so a one-hour lag in the change of gate position didn't cause serious issues - but it does in the daily model. The trouble is, I need a daily model to reduce the number of calculati...
- Tue Nov 13, 2018 8:13 pm
- Forum: Vensim
- Topic: Changing the order of calculations
- Replies: 10
- Views: 5449
Changing the order of calculations
I'm running a hydropower operations model using Vensim. I noticed that the order of calculations is wrong and as such is causing unreasonable results... I have a stock for the spillway gate position, and the value of this should be computed before the gated spill release is calculated. Because the i...
- Fri Aug 10, 2018 12:40 am
- Forum: Vensim
- Topic: How to determine equation ordering?
- Replies: 3
- Views: 2283
Re: How to determine equation ordering?
Thanks. It works. I'm not using PySD as it cannot handle all the subscripts yet. My Vensim model relies on GAME variable inputs from Python as well. So I'm trying a couple of options, one uses SDEverywhere and interfaces it with Python using Cython callbacks, the second option is using the compiled ...
- Wed Aug 08, 2018 8:01 pm
- Forum: Vensim
- Topic: How to determine equation ordering?
- Replies: 3
- Views: 2283
How to determine equation ordering?
I'm working on converting a vensim model to run in a C/Python environment so it can run on a Linux supercomputing environment. In order for this converted model to get the same results, it is crucial to check the ordering of equation calculations somehow. Any suggestions?
- Wed Dec 06, 2017 7:26 pm
- Forum: Vensim
- Topic: How can I use Vensim DLL in Python, Linux?
- Replies: 8
- Views: 7143
Re: How can I use Vensim DLL in Python, Linux?
Has anybody tried the Multi-context DLL to get Vensim projects running on Linux? Would love some advice on where to begin with this and whether it's possible before I purchase the multi-context license.