Search found 3806 matches

by tomfid
Tue May 23, 2023 8:14 pm
Forum: Vensim
Topic: Delay of random pulses
Replies: 7
Views: 1421

Re: Delay of random pulses

Try this?
pulse.mdl
(2.56 KiB) Downloaded 119 times
by tomfid
Tue May 23, 2023 8:03 pm
Forum: Vensim
Topic: Delay of random pulses
Replies: 7
Views: 1421

Re: Delay of random pulses

What's the purpose of this? If we knew, there might be some easier alternative.

You could certainly use SAMPLE IF TRUE, or the equivalent stock formulation, to store the height of the previous pulse, until needed when the next one occurs.
by tomfid
Sat May 20, 2023 1:03 am
Forum: Vensim
Topic: Showing maximum Slope
Replies: 5
Views: 1091

Re: Showing maximum Slope

You can use SAMPLE IF TRUE if you're trying to capture the maximum over time.
by tomfid
Mon May 15, 2023 2:55 pm
Forum: Vensim
Topic: Seeking Guidance on Using Tabbed Array Function in Vensim Pro
Replies: 3
Views: 941

Re: Seeking Guidance on Using Tabbed Array Function in Vensim Pro

I just noticed that the equation in your screenshots doesn't have any subscripts. That's why it's not working - you're supplying multiple values for a single variable.

Click the "subscripts" button in the equation editor and add some dimensions to the variable.
by tomfid
Sat May 13, 2023 2:04 pm
Forum: Vensim
Topic: Seeking Guidance on Using Tabbed Array Function in Vensim Pro
Replies: 3
Views: 941

Re: Seeking Guidance on Using Tabbed Array Function in Vensim Pro

There's a sample model in the Help system.
https://www.vensim.com/documentation/fn ... array.html

Unless the array is large and needs to be pasted in from a spreadsheet, I find normal punctuation easier. You can define

Code: Select all

x[a,b]=
1,2,3;
4,5,6;
The order is rows=a, columns=b.
by tomfid
Thu May 11, 2023 2:43 am
Forum: Vensim
Topic: "Blocked for this application" error
Replies: 15
Views: 2334

Re: "Blocked for this application" error

Works for me too ... but there are a lot of models. Is the problem in a particular one?
by tomfid
Tue May 09, 2023 4:09 pm
Forum: Vensim
Topic: Connecting with data
Replies: 8
Views: 1486

Re: Connecting with data

In the example, 'data' is a variable name. There are a lot of possible layouts, including Tidy an relational, but typically something like this is easiest: 2023-05-09_10-07-17.png In the import dialog, you'll specify the "sub" columns as subscripts. The range names in the first row don't m...
by tomfid
Tue May 09, 2023 4:01 pm
Forum: Vensim
Topic: Connecting with data
Replies: 8
Views: 1486

Re: Connecting with data

I think the issue you raise in #4 may be avoidable if you put cell addresses in an arrayed string function, but direct import from .csv or .tab is likely to be cleaner.
by tomfid
Tue May 09, 2023 3:57 pm
Forum: Vensim
Topic: Connecting with data
Replies: 8
Views: 1486

Re: Connecting with data

If the Age x Operation x Health Trust matrix has a lot of empty elements, Ventity might be a good alternative. For example, a while ago I prototyped a model of consumer products, with detail like Market (country) x Flavor x Size. Not every flavor x size is offered in every country, so the full matri...
by tomfid
Tue May 09, 2023 3:49 pm
Forum: Vensim
Topic: Connecting with data
Replies: 8
Views: 1486

Re: Connecting with data

There's a chapter in the User Guide, https://www.vensim.com/documentation/21160.html

Last year's conference workshop is online https://vensim.com/conference/#using-data-in-vensim
by tomfid
Mon May 08, 2023 3:15 am
Forum: Vensim
Topic: read_ini file
Replies: 12
Views: 1902

Re: read_ini file

If you let us know what functionality you're missing, it's likely that we can implement it in the new GUI more quickly than we can fix the old.
by tomfid
Fri May 05, 2023 12:39 pm
Forum: Vensim
Topic: Unit Check Error
Replies: 7
Views: 1467

Re: Unit Check Error

This is not a known issue, and therefore hard to diagnose without a sample.
by tomfid
Tue May 02, 2023 1:24 pm
Forum: Vensim
Topic: Data import from excel question
Replies: 2
Views: 1209

Re: Data import from excel question

We would need a more specific question or example to work with.

Have you checked the User Guide in the help system?
https://www.vensim.com/documentation/usr16.html

Also:
https://vensim.com/conference/#using-data-in-vensim
by tomfid
Fri Apr 28, 2023 12:58 am
Forum: Vensim
Topic: Step pattern
Replies: 6
Views: 1438

Re: Step pattern

Consider the following setup: p = PULSE TRAIN( ... ) v = INTEG( p, 0 ) The discrete integration via Euler's method takes steps like: v(time+time step) = v(time) + time step*p This makes it easy to see why the steps are small when TIME STEP is small. If instead you integrate: v = INTEG( p/TIME STEP, ...
by tomfid
Wed Apr 26, 2023 9:45 pm
Forum: Vensim
Topic: Step pattern
Replies: 6
Views: 1438

Re: Step pattern

In other words, use a level to integrate a PULSE TRAIN.

Another option would be to use the ramp, and feed it to the QUANTUM function to make steps. QUANTUM is like INTEGER but with an arbitrary step size.
by tomfid
Tue Apr 25, 2023 11:02 pm
Forum: Vensim
Topic: Calculating demand
Replies: 1
Views: 1091

Re: Calculating demand

It's hard to say what's going wrong without an example model. However, one possibility is that what you're suggesting is not possible. If clothes last 7 years, then at most 1/7th can go to the landfill per year. In any case, your decision rule for buying new clothes must: - replace clothes discarded...
by tomfid
Tue Apr 25, 2023 4:44 pm
Forum: Vensim
Topic: "Blocked for this application" error
Replies: 15
Views: 2334

Re: "Blocked for this application" error

You can google the same via "site:www.ventanasystems.co.uk resource file" - but it won't help because there's evidently an installer bug - I can replicate your experience. We'll get it fixed ASAP.
by tomfid
Sat Apr 22, 2023 12:07 pm
Forum: Vensim
Topic: "Blocked for this application" error
Replies: 15
Views: 2334

Re: "Blocked for this application" error

One possibility is that it uses subscripts, which won't work in PLE. You could try opening it with the free Model Reader instead.
by tomfid
Fri Apr 21, 2023 11:44 pm
Forum: Vensim
Topic: Vensim works according to a mathematic equations? Anyone can help me, please?!
Replies: 7
Views: 1786

Re: Vensim works according to a mathematic equations? Anyone can help me, please?!

There isn't really an easy, general way to do this, but you could do something like the following. You have 3 stocks, but since they're conserved, there are really only 2 degrees of freedom. So you could parameterize the initial values of the stocks as something like: neutral = population * frac neu...
by tomfid
Fri Apr 21, 2023 1:11 pm
Forum: Vensim
Topic: Screen display
Replies: 4
Views: 1335

Re: Screen display

Setting the zoom to a fixed level should solve this.

Also, you may want to hide variables rather than deleting them. That way you can do everything in one model, and even one view.
by tomfid
Thu Apr 20, 2023 4:31 pm
Forum: Vensim
Topic: No Mail received for PLE-download
Replies: 4
Views: 1177

Re: No Mail received for PLE-download

I just made some changes to our mail configuration that *might* help with web.de in the future. Some hosts are just really aggressive at filtering and therefore create some false positives unfortunately.
by tomfid
Thu Apr 20, 2023 2:13 pm
Forum: Ventity
Topic: Documentation bug?
Replies: 2
Views: 2778

Re: Documentation bug?

Ticketed for improvement.
by tomfid
Thu Apr 20, 2023 2:10 pm
Forum: Vensim
Topic: Query about analytical equations
Replies: 3
Views: 1253

Re: Query about analytical equations

Not at present, but the Doc tool is slated for an update, so I'll add this to the list.
by tomfid
Thu Apr 20, 2023 12:38 pm
Forum: Vensim
Topic: Vensim works according to a mathematic equations? Anyone can help me, please?!
Replies: 7
Views: 1786

Re: Vensim works according to a mathematic equations? Anyone can help me, please?!

There are some unit errors here that could indicate the problem. The first is that "unitless" is not a known synonym for "dimensionless" (which Vensim understands). You can add an entry to Model>Settings>Units, like dmnl,dimensionless,unitless After that, there are still some iss...