I think the rules are much like those for .cin files,
https://www.vensim.com/documentation/ci ... q=Comments
If you look at a .out file (which can be reused as a voc), you'll see comments like:
:COMSYS After 22610 simulations
Just the :C should be sufficient.
Spaces should be OK.
Search found 3816 matches
- Fri May 17, 2024 4:35 pm
- Forum: Vensim
- Topic: Adding Comments to Calibration VOC
- Replies: 2
- Views: 87
- Thu May 09, 2024 7:20 pm
- Forum: Vensim
- Topic: Automated multiple simulations in PLE+?
- Replies: 6
- Views: 185
Re: Automated multiple simulations in PLE+?
A quick way to do this would be to vary the noise seed in Synthesim, changing the run name each time. You can do this one of the following ways: A. Create a variable called NOISE SEED, with value 1 (or any other integer). Set the range to something like 1 ... 1000 and the interval to 1. In your rand...
- Thu May 09, 2024 7:16 pm
- Forum: Vensim
- Topic: Sensitivity2All
- Replies: 13
- Views: 340
Re: Sensitivity2All
You should be able to replicate the error manually. Just do a run with the first reported problem, manually changing additional cooling tariff kwh as shown.
When you choose "simulate 1 param +/- 10%" it creates ordinary runs that will appear in the dataset control, on plots, etc.
When you choose "simulate 1 param +/- 10%" it creates ordinary runs that will appear in the dataset control, on plots, etc.
- Thu May 09, 2024 7:12 pm
- Forum: Vensim
- Topic: Sensitivity2All
- Replies: 13
- Views: 340
Re: Sensitivity2All
The thread affinity warnings are benign. It just means the operating system declined to assign requested threads. Presumably this is Windows, where thread management is not as good as Linux. It won't affect results. The crash might be related to the floating point errors in the model. Did you submit...
- Wed May 08, 2024 3:12 pm
- Forum: Vensim
- Topic: Sensitivity2All
- Replies: 13
- Views: 340
Re: Sensitivity2All
Surely S2A = Sensitivity2all
- Sun Apr 21, 2024 1:22 pm
- Forum: Vensim
- Topic: Integration techniques: Impacts on Stock behavior
- Replies: 5
- Views: 780
Re: Integration techniques: Impacts on Stock behavior
I think Aliakhavan89 is on the right track. However, it's impossible to give a precise answer without more information than the chart provides. What are the TIME STEP and SAVEPER? Presumably 12000 hours from eyeballing the chart? What is the equation for end use efficiency? A step * exponential? Or ...
- Sun Apr 21, 2024 1:12 pm
- Forum: Vensim
- Topic: Death by Subscript
- Replies: 6
- Views: 606
Re: Death by Subscript
SUM is definitely the summation operator Sigma. The exclamation point is not useless; it is necessary in cases where you'd like to sum over a subset of the dimensions belonging to the right side. I would write the equation in your image with something like the following: n : n1, n2 s : <something> a...
- Sat Apr 20, 2024 11:27 pm
- Forum: Vensim
- Topic: Death by Subscript
- Replies: 6
- Views: 606
Re: Death by Subscript
Looking at the model may not be required, but I'm not sure an answer can be given from the material here. What you're showing seems syntactically valid, so the problem may be somewhere else. What are the definitions of h and pressure number? What is on the left side of the sum expression? Is h the e...
- Sun Apr 14, 2024 9:49 pm
- Forum: Vensim
- Topic: SINTEG with vars
- Replies: 4
- Views: 616
Re: SINTEG with vars
Probably not, but you could modify your flow equations to do the same thing. We'd have to have a concrete example to comment on.
- Mon Apr 01, 2024 2:23 pm
- Forum: Vensim
- Topic: two imodels with no significant differences behaving differently
- Replies: 2
- Views: 561
Re: two imodels with no significant differences behaving differently
#2 has the Simulate>Based On setting active, which might change the lookup.
- Thu Mar 28, 2024 6:17 pm
- Forum: Vensim
- Topic: double-click selection
- Replies: 5
- Views: 3359
Re: double-click selection
Some of this will change with the new equation editor soon.
- Thu Mar 28, 2024 6:16 pm
- Forum: Vensim
- Topic: How to calculate the difference in value for a variable in vensim over time?
- Replies: 2
- Views: 1746
Re: How to calculate the difference in value for a variable in vensim over time?
You can use DELAY FIXED for this: Previous GDP = DELAY FIXED( Current GDP, one year, Current GDP ) ~ $/year one year == 1 ~ year In continuous time, you can use the SMOOTH function, i.e. Previous GDP = SMOOTH( Current GDP, one year ) ~ $/year You can also use the TREND function to compute a fraction...
- Thu Mar 21, 2024 1:11 am
- Forum: Vensim
- Topic: it is frustrating!
- Replies: 25
- Views: 4565
Re: it is frustrating!
Is the run "current" the first loaded dataset?
- Thu Mar 21, 2024 1:10 am
- Forum: Vensim
- Topic: Continuos or discrete variables?
- Replies: 4
- Views: 2552
Re: Continuos or discrete variables?
On the other hand, if you're interested in stochastic extinction of a disease in a small population, integer values may matter.
It's impossible to answer these questions in general; some specifics of the question to be answered must be known.
It's impossible to answer these questions in general; some specifics of the question to be answered must be known.
- Thu Mar 21, 2024 1:08 am
- Forum: Vensim
- Topic: Continuos or discrete variables?
- Replies: 4
- Views: 2552
Re: Continuos or discrete variables?
Like Forrester, I think that discrete quantities are rarely a good place to start. Things that are theoretically only available in integer quantities either don't matter, or have qualifications. For example, people are certainly available in integer quantities. But what about the work-equivalent of ...
- Thu Mar 21, 2024 1:04 am
- Forum: Vensim
- Topic: Continuos or discrete variables?
- Replies: 4
- Views: 2552
- Fri Mar 08, 2024 3:57 pm
- Forum: Vensim
- Topic: Help with PULSE TRAIN and random variable
- Replies: 6
- Views: 2384
Re: Help with PULSE TRAIN and random variable
Try this instead ...
You can also use SAMPLE IF TRUE for this (though I think it's not available in all versions).
You can also use SAMPLE IF TRUE for this (though I think it's not available in all versions).
- Tue Mar 05, 2024 2:06 pm
- Forum: Vensim
- Topic: it is frustrating!
- Replies: 25
- Views: 4565
- Mon Mar 04, 2024 4:36 pm
- Forum: Vensim
- Topic: where is the sim set up from the old GUI in the new one?
- Replies: 9
- Views: 20550
Re: where is the sim set up from the old GUI in the new one?
Not sure I'm tracking the issue here. In the old gui, PLE sim setup doesn't have a dialog. Everything is in the toolbar. 2024-03-04_09-33-54.png In the new gui, PLE does have a dialog (albeit without much content). 2024-03-04_09-32-44.png In both cases, constants and lookups are highlighted, and you...
- Mon Feb 05, 2024 11:10 pm
- Forum: Vensim
- Topic: Reinstall Vensim (error 977).
- Replies: 5
- Views: 1132
Re: Reinstall Vensim (error 977).
Typically this indicates a path problem. Have you moved the dll?
- Fri Feb 02, 2024 4:00 pm
- Forum: Vensim
- Topic: RC Fonksiyon
- Replies: 1
- Views: 894
Re: RC Fonksiyon
I think you'll have to elaborate a bit, because there are a lot of different possible population structures, which might call for different approaches.
One option is to use the Little's Law equilibrium estimate, i.e. residence time = stock/flow_throughput. https://en.wikipedia.org/wiki/Little%27s_law
One option is to use the Little's Law equilibrium estimate, i.e. residence time = stock/flow_throughput. https://en.wikipedia.org/wiki/Little%27s_law
- Fri Feb 02, 2024 2:00 pm
- Forum: System Dynamics Discussion
- Topic: Utilizing Ventana Systems Tools for enhancing data breach protection strategies ?
- Replies: 3
- Views: 2994
Re: Utilizing Ventana Systems Tools for enhancing data breach protection strategies ?
For starters, google "sander zeijlemaker security system dynamics" - he's done quite a bit of interesting work. You should be able to find much of it in the ISDC conference proceedings.
- Fri Feb 02, 2024 1:52 pm
- Forum: Vensim
- Topic: Can the Vensim PLE version achieve seasonal forecasting?
- Replies: 2
- Views: 1032
Re: Can the Vensim PLE version achieve seasonal forecasting?
I think the month variable is intentional, for creating a seasonal input.
Since the seasonal behavior has 3 episodes, switched in an IF THEN ELSE statement, I think you could create the same thing for seasonal smoothing - have 3 smoothing structures, one active during each episode.
Since the seasonal behavior has 3 episodes, switched in an IF THEN ELSE statement, I think you could create the same thing for seasonal smoothing - have 3 smoothing structures, one active during each episode.
- Thu Feb 01, 2024 3:45 pm
- Forum: Vensim
- Topic: Units tips or laws
- Replies: 7
- Views: 1550
Re: Units tips or laws
Your flows are dimensioned dmnl/hour, but your time unit in Model>Settings is Mes.
- Wed Jan 31, 2024 3:57 pm
- Forum: Vensim
- Topic: Units tips or laws
- Replies: 7
- Views: 1550
Re: Units tips or laws
There are at least two rules: - a flow has the same units as the stock it connects to, divided by the time unit - EXP, LN, and a number of other functions require dimensionless units beyond that, if you have y = a / b the units follow y units = a units/b units One consequence of this is that you can...