Search found 3808 matches

by tomfid
Tue Jun 10, 2014 6:44 pm
Forum: Vensim
Topic: Vensim 6.3 released
Replies: 0
Views: 4251

Vensim 6.3 released

See http://vensim.com/vensim-6-3-released/ for details & downloads.
by tomfid
Mon Jun 09, 2014 5:32 pm
Forum: Vensim
Topic: Gaming with subscripts
Replies: 12
Views: 7151

Re: Gaming with subscripts

I think the error persists because "error" is in some of the subscript definition fields. How it got there in the first place appears to be a bug in the Add Subscripts menu command. However, the bug only occurs when subscripts are added to a particularly anomalous model, like the original ...
by tomfid
Mon Jun 09, 2014 3:25 pm
Forum: Vensim
Topic: PULSE TRAIN function
Replies: 2
Views: 2249

Re: PULSE TRAIN function

Right - there's a sample model in the help system that illustrates this. http://www.vensim.com/documentation/fn_pulse_train.htm
by tomfid
Fri Jun 06, 2014 4:49 pm
Forum: Vensim
Topic: Gaming with subscripts
Replies: 12
Views: 7151

Re: Gaming with subscripts

Try starting from this:
hotels_full_service_multiple 2.mdl
(3.01 KiB) Downloaded 265 times
by tomfid
Fri Jun 06, 2014 4:45 pm
Forum: Vensim
Topic: Gaming with subscripts
Replies: 12
Views: 7151

Re: Gaming with subscripts

I can replicate the varformat error. But it seems that the original model is not in a working state, prior to attempting to add the subscript. Many of the variables are defined as data, and therefore are missing their equations.
by tomfid
Fri Jun 06, 2014 4:09 pm
Forum: Vensim
Topic: Error: Gaming file corrupted
Replies: 3
Views: 2336

Re: Error: Gaming file corrupted

Also, is this a venapp, or just a model? If the latter, the first places I'd look would be (a) the simulation control dialog (Model>Simulate menu), Changes tab, Based On field, (b) simulation control Advanced tab, Data Sources field, and (c) the filename passed in GET VDF functions in the equations,...
by tomfid
Wed Jun 04, 2014 11:57 pm
Forum: Vensim
Topic: Vensim and xmile
Replies: 2
Views: 2122

Re: Vensim and xmile

BTW, what's your interest here? Migrating a few big models? Browsing models across platforms? ... ? (We're curious because it affects how we prioritize different aspects of the implementation.)
by tomfid
Wed Jun 04, 2014 9:36 pm
Forum: Vensim
Topic: Vensim and xmile
Replies: 2
Views: 2122

Re: Vensim and xmile

Not yet. We do plan to support it at some point, but we've been too busy working on new tools.
by tomfid
Thu May 15, 2014 6:38 pm
Forum: Vensim
Topic: How to Solve error comes???
Replies: 2
Views: 2037

Re: How to Solve error comes???

The general strategy here is to plug in the parameters reported as causing the error,

Code: Select all

R1 = 0.397753
R5 = 0.196305
R10 = 0.475031
W = 0.203637
and run an ordinary simulation to see what the error is.
by tomfid
Mon Apr 28, 2014 9:30 pm
Forum: Vensim
Topic: Base Variable on the Graph (Venapp)
Replies: 11
Views: 4729

Re: Base Variable on the Graph (Venapp)

If that's not it, I think I'd have to see an example.
by tomfid
Mon Apr 28, 2014 9:29 pm
Forum: Vensim
Topic: Base Variable on the Graph (Venapp)
Replies: 11
Views: 4729

Re: Base Variable on the Graph (Venapp)

No - but one thing to check is whether you inadvertently exited without saving your analysis toolbar settings - you may be back to "Selected Vars" on the graph tool.
by tomfid
Fri Apr 25, 2014 1:54 am
Forum: Vensim
Topic: Base Variable on the Graph (Venapp)
Replies: 11
Views: 4729

Re: Base Variable on the Graph (Venapp)

I think this may be a bug - we'll have to investigate - but I think something goes wrong when the "Selected Vars" option is checked in the graph tool. Try right-clicking your graph tool in the analysis toolbar and unchecking that setting (near bottom left).
by tomfid
Wed Apr 23, 2014 3:50 am
Forum: Vensim
Topic: Running a model in hours, keeping track of days....
Replies: 4
Views: 4751

Re: Running a model in hours, keeping track of days....

One strategy to think about, somewhat common in electric power modeling, would be to simulate only representative times per day or days per month/season. You could also potentially move some of the hourly detail off the time axis and into an array dimension, if serial correlation isn't a big deal.
by tomfid
Tue Apr 22, 2014 1:32 pm
Forum: Vensim
Topic: Base Variable on the Graph (Venapp)
Replies: 11
Views: 4729

Re: Base Variable on the Graph (Venapp)

Are you actually developing a model with graphs on the diagrams, using the Input/Output object with a workbench variable? (If so, I think I may know what's happening.)
by tomfid
Tue Apr 22, 2014 1:29 pm
Forum: Vensim
Topic: Problem with Vensim
Replies: 3
Views: 2106

Re: Problem with Vensim

If you can send us a copy of the model, we might be able to track it down. We haven't changed anything in the diagramming that I'm aware of.
by tomfid
Mon Apr 14, 2014 1:07 pm
Forum: Vensim
Topic: Can't figure out how weight and payoff work in calibration
Replies: 7
Views: 4740

Re: Can't figure out how weight and payoff work in calibrati

If your errors are normally distributed and the payoff is properly weighted according to the standard errors, the expected value of the payoff is the number of data points.

Also, check the payoff report (*.rep file) for additional diagnostic stats.
by tomfid
Mon Apr 07, 2014 1:03 pm
Forum: Vensim
Topic: Subscripts
Replies: 2
Views: 2310

Re: Subscripts

That's the right syntax. What do you mean by "not working" ?
by tomfid
Sun Apr 06, 2014 2:51 am
Forum: Vensim
Topic: about floating error
Replies: 4
Views: 2560

Re: about floating error

When a model has explosive floating point errors like this, it's generally useful to re-run it for a short time (like 2014-2018 in this case) to make it easier to see what's going on. Also, if you're using an advanced version, right-click the Table tool and set it to show "Causes" rather t...
by tomfid
Tue Apr 01, 2014 12:33 am
Forum: Vensim
Topic: type of distribution for sensitivity analysis
Replies: 2
Views: 1778

Re: type of distribution for sensitivity analysis

You can often transform a UNIFORM variable to the needed distribution, for example:
http://en.wikipedia.org/wiki/Fr%C3%A9ch ... tributions
by tomfid
Tue Apr 01, 2014 12:31 am
Forum: Vensim
Topic: Approaches for Different Units by Subscript Value?
Replies: 2
Views: 1971

Re: Approaches for Different Units by Subscript Value?

I think your solution is about as good as it gets, unfortunately. Will ponder...
by tomfid
Tue Apr 01, 2014 12:27 am
Forum: Vensim
Topic: Lookups vs data variables
Replies: 2
Views: 1856

Re: Lookups vs data variables

Was the kidney for a copy of Business Dynamics? At least it's a good trade. You can suppress the lookup warning by normalizing time, as in Rainfall = Rainfall Lookup( Time/one year ) where one year is a constant with units appropriate to cancel time units. Data is generally preferable for at least o...
by tomfid
Thu Mar 27, 2014 7:56 pm
Forum: Vensim
Topic: Mapping from one set of subscripts to another
Replies: 4
Views: 2216

Re: Mapping from one set of subscripts to another

There are lots of other esoteric possibilities, so feel free to ask further!
by tomfid
Wed Mar 26, 2014 4:06 am
Forum: Vensim
Topic: How to output the table of "Mean Value" by Monte Carlo Simul
Replies: 3
Views: 2152

Re: How to output the table of "Mean Value" by Monte Carlo S

If you right-click the Bar Graph and Statistics analysis tools, you can change their settings to display results across sensitivity simulations.