Ventana software support forum

I'm working on this. In a sense, there isn't an "aging" mechanism in a Ventity cohort model. You don't have to move people from one cohort to another. You keep track of a list of cohorts, add new cohorts, and delete old ones if they're (nearly) empty. Anything that's inside a single entity...

Select the item, then hit the <Delete> key.

I'm happy to announce that we've just uploaded a new Ventity beta (build 573). Some of the bigger changes are documented in the Release Notes (see "What's New" in the Help system), but there are also many small usability improvements, particularly to things like diagramming and predictive ...

I don't use capitalization for anything other than appearance. Adding a lot of tags clutters things and makes the model look geeky to non-technical viewers. I prefer to let the words do the work: stock: noun (people in house, capital) flow: gerund or explicit "rate" (exit rate, investing) ...

Win10 does seem to be an improvement all around. I haven't had any issues. The Win8 update issue seems to be resolved as well.

Thanks ... I'll check it out.

It might be easiest to generate arrivals for each origin-destination pair independently. See attached for an example.

The data variable won't contain any interpolated or held points, but when it's used, you'll see them downstream.

For example, try:

myData := GET XLS DATA( ... )
myAux = myData

Then play around with the interpolation pattern and take a look at myAux.

Use the :HOLD BACKWARD: keyword.

https://www.vensim.com/documentation/in ... ations.htm

You can use the DELAY FIXED function to create a stock representing the 3-year moving accumulation. For example:

profit = ...
cumulative profit = INTEG( adding - removing, 0 )
adding = profit
removing = DELAY FIXED( profit, horizon, 0 )
horizon = 3
average profit = cumulative profit / horizon

https://www.vensim.com/documentation/in ... f_true.htm

https://www.vensim.com/documentation/in ... _stats.htm

We haven't implemented any of the dynamic functions yet - we're waiting on a bit of development for an internal capability something like Vensim MACRO functions. Some of the complex delays, like conveyors, probably won't be implemented, because they can be done better by creating cohorts of entities...

Good idea. We'll see what we can cook up. It may be tricky in some situations, because there are things Ventity does that will be hard to represent in Vensim.

It seems like the paper doesn't fully document the models and experiments, so it's hard to know what's missing.

Fixing units is a good start, but I'd email the authors and see if the model, or at least an equation listing, is available.

I can ask around. You might also try asking on the SD discussion forum.

It would help to have a description of what you're trying to achieve with this calculation. There might be an easier way.

To use find zero, you'd have to define a one-dimensional array i_j of size ELMCOUNT(i)*ELMCOUNT(j) and map t[i,j] to t2[i_j]. Then you could use the find zero functionality to iterate.

This would probably work better as an external function though.

Here's a double precision .vdf:

The only simple, general answer is to switch to a double precision Vensim version. You would have exactly the same problem if you were working in a programming language using floats instead of doubles. But why does this matter in practice? It would be very unusual for a real system to be free of dis...

It's possible with subscripting. Take a look at this: I did this once before, long ago, and the result was more elegant as I recall, so perhaps someone can improve on it.

I don't think there's a way to make the exact technical problem go away in general; I'd have to know something about the specific problem to suggest a practical solution.

This is a limitation of single-precision number representation. In Vensim DSS double precision, the model comes exactly into equilibrium.

There isn't any document, or interoperability, yet. We will create a translator for Vensim models to Ventity, most likely via XMILE. Simple models and components should translate ~100%. We don't expect full two-way translation of models to be practical. Coming from Vensim, it doesn't make sense to m...

I just downloaded, installed and ran PLE 5.11 on a Win8.1 x64 machine, and it worked fine. Perhaps your downloaded file really is corrupted. Try the download again?

"Arcane" may not be the best word. However, in my experience, there are often a few points in a model, usually where the dimensionality is changing, that do require very complex and opaque subscripting. Now that I've been using Ventity for a little while, I'm also finding it annoying to ha...