Ventana software support forum

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 ...

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...

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...

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.

#2 has the Simulate>Based On setting active, which might change the lookup.

Some of this will change with the new equation editor soon.

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...

Is the run "current" the first loaded dataset?

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.

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 ...

Try this instead ...
You can also use SAMPLE IF TRUE for this (though I think it's not available in all versions).

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...

Typically this indicates a path problem. Have you moved the dll?

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

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.

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.

Your flows are dimensioned dmnl/hour, but your time unit in Model>Settings is Mes.

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...

If you open them in the same application instance, this works. (If you open the files by double-clicking from the finder/explorer, you have two application instances, and it won't work.)

In pro/DSS, general settings, you can enable opening multiple models simultaneously.

I think the 3221226505 return code may be a variable type mismatch - this has been reported in other contexts.

If you can make the calculation at FINAL TIME, you can use SAMPLE IF TRUE to hold the max value over the simulation - there's an example in the help system.

In a case like this, importing the data to vdf would be less error-prone.

The GET DATA calls are basically 1-dimensional because the spreadsheet is 2D, and one is taken by time.

One possible way to semi-automate a GET call with more dimensions is to put the sheet names or first-cell references in a string variable with the appropriate subscripting.