Ventana software support forum

Right. Personally I find it hard to remember the beginning/ending balance sequencing. It would be nice if we could update the table tool to make it easy to toggle display of stocks as start/end of period, though that might be tricky for some variables using functions like SAMPLE IF TRUE. It would al...

I think that the computation is actually correct. The Euler update in your spreadsheet is: stock(t + dt) = stock(t) + flows This is fine if the TIME STEP (dt) = 1, but in this model it's 0.25. The correct Euler update is: stock(t + dt) = stock(t) + flows*dt In this case, the value 1618 in cell F37 i...

I agree. The drawback of a lookup is that it might not be totally general (i.e. you'd have to recompute the values if some assumption changed). My guess is that the speed penalty for FIND ZERO is small. Unfortunately, you can't wrap FIND ZERO in an INITIAL statement, but you could set the error vect...

Another option would be to put a table of solutions (Moody diagram) into a lookup or fitted function.

This means there are syntax errors in the equations. Use Check Model <ctl><T> to see the error window.

Newer Stella models are in XMILE, which you can import via the File menu.

Whether variables remain in the model depends on user choice - when you delete a variable with the delete key, a dialog asks whether to remove them from the model or only the current view. You can find these variables by opening the Control Panel > Variables tab, and selecting the "orphans"...

I can replicate this. Ticketed for the devs to take a look.

It's working right now. There was an intermittent issue that seems to be resolved with our last web site update. Sorry for the issue.

Notice here that the COUNTRIES range is built up hierarchically by first defining euro and non-euro subranges. That's not necessary however - you can mix & match ranges and elements. City : Boston, Las Vegas, Denver, San Diego, Seattle, New York East Coast : Boston, New York West Coast : San Die...

It sounds like you want a population stock that's moving approximately alongside the data from 1995-2023, then reset the population stock to precisely match the data at 2023, then have the population evolve into the future by endogenous forces? If so, there are several ways to do this. The general i...

If the endpoint is fixed, you can use the approach of creating a variable.

If the endpoint is uncertain, specifically, not known at the start of the run, there isn't really a way to do this, except by postprocessing the output in some other tool (Excel, R, Python ...)

You can use these distributions either in equations, or via the sensitivity (Monte Carlo) tool.

Is there something specific that you need from the older interface?

There isn't a way to link to a spreadsheet in PLE.

Or perhaps what you're looking for is an export of the dataset to Excel? Use Model>Export Dataset.

I think there's an efficiency issue here. Because the 'identify' and 'update' triggers are in the Region entity, they're executing multiple times - i.e. every region is identifying the best region. I can think of a couple alternatives. - Move the trigger to a singleton entity like the Model. Putting...

1 - the PULSE TRAIN function might work

2 - you can solve this, but it may not be the best choice - https://metasd.com/2017/01/forrester-on ... ous-flows/

For inspiration, you might look to
C:\Users\Public\Vensim\Models\Sample\EXTRA\COMMOD.MDL
which installs with Vensim.

I think your first step should be to adopt standard stock-flow notation in your diagram. Currently you have no flows, so your are integrating earlier age categories directly into later age categories, like Bull= INTEG ( -Bull+"Bullock 12-18", 0) Units: number ******************************...

I think this is already ticketed - it's happening in other models as well. I was under the impression that 10.1 fixed it.

When I use File>Save from the Document tool window, I get the usual Save As dialog with type .txt, prompting me to name the file. The default location is the folder containing the model. Do you get a different behavior? Are you using v10 and the new gui?

I think the task here is actually a little bigger. Since .vdfx went to double precision, there's been a mismatch between the engine/output numerical precision and text precision. For example, you can read in a constant from a .cin file as a float or a double, but a constant in an equation gets trunc...

Judging by the paths, this has to be Windows, so the key question is what Vensim version?

File>Publish is unrelated to the Doc tool. You probably just want to click the Doc tool and save the resulting window.