Ventana software support forum

Hello, I am using the VensimDLL to analyze Vensim models in Mathematica. Doing this I will build a model graph using the adjacency information provided by listing the causes and uses of a variable (e.g. a graph-vertex) when applying the DLL function VensimGetVarAttrib . I just noted that there seems...

Thank you, Tom, the message has come through.

Hello Tom, I have put myself on the list but have not received any info so far including my spam folder. Should I be missing on your list of interested people for some reason I would greatly appreciate being listed. Also please forward the message that I have missed. Best regards, Guido mailto:gwr@b...

@Tom:

The launch is a bit slower than we'd hoped, but it's in alpha with a few people. We'll say a bit more tomorrow.

Did I miss something or have there really not been any annoucements with regard to Ventity since your announcement of an announcement?

Best,
Guido

Thank you, that is helpful, so I will not have to ponder "double" vs. "int" issues probably. The issue with the false format (loading 64Bit from 32Bit or vice versa) should pertain to .NET and thus might be reproduced from other 64Bit applications? Anyhow it is good to find this ...

Yes, I am using x64 Mathematica, and accordingly sofar with the 32BIT Vensim DLLs I had to use:
for it to work - which it did nicely.

Hello, I greatly appreciate the availability of a 64Bit version of Vensim. Unfortunately I am running afoul linking the 64-Bit DLL ("vendll64.dll") to Mathematica which worked fine with the 32-Bit DLLs (Single and Double Precision). The documentation has not been adapted with regard to the...

D'accord, JJ. There is one more thing that I feel uncomfortable with and that may need taking care of differently: I do find it unfortunate that :NA: is not a symbol but a numerical value. It sometimes gives annoying error-messages, for example if the range of possible values has been set to 0 you g...

Hi JJ, I totally agree that in principle strict unit checking should be enforced. But in lieu of additional functionality I do find it annoying to be forced to explicitly write a separate equation every time which in sketch mode also means additional mouse movements. It would be clearer to go -- as ...

Hi Phil, I am just a bit curious: Are you sure that you are addressing a dynamic problem here? The ticket sales forcasting sounds rather like food for multivariate regression analysis or some fancy machine learning algorithm. Best, Guido PS: I do find the question about Ventity's release date a very...

I have added a Quantity( magnitude, units ) - like expression to the Vensim wish list:

http://www.ventanasystems.co.uk/forum/v ... =50#p20139

I noted repeatedly that unit checking runs afoul when numerical values are used in equations. For example in a macro I used an IF THEN ELSE construct that checked for a parameter being :NA: result = IF THEN ELSE( input = :NA: , {THEN} result 1, {ELSE} some function of the input ) ~ correctUnits ~| V...

I consider it "cumbersome" because SI-prefixes are not separated from fundamental units. Once "kilo" is defined as a dimensionless prefix, as I have indicated in the model enclosed above, I will not need another conversion factor if I use "kilo" again for say meters or ...

It is quite interesting to note that the "division of entities with the same physical dimensions" is to lead to anything else but a dimensionless number. To me as an admitted lay physicist this seems to totally contradict the central tenets of dimensional analysis in the wake of Fourier an...

Having come upon this thread from my own question regarding "reporting annual (accounting) flows in a bar graph" ( http://www.ventanasystems.co.uk/forum/viewtopic.php?f=2&t=5749 ) I found that I had the same problem: some flow (usually an accounting flow) is to be reported as an averag...

Hi yps, no, there are no FOR-loops in Vensim and the question remains: What exactly do you need them for? (As I have shown in the case you have presented there is a closed form for the result so no need to iterate.) If you do have an upper limit for n you might use subscripts and mappings to achieve...

Thanks, Wilson! Your solution is very much what I would like to see and seems to be 'as close as one can get' as of now. I would probably want to put the integration of the flow into a macro (cf. Tom's suggestion for a similar question that I have cited in the PS to my original post) which unfortuna...

Hi,

hacking this into Mathematica reveals that the solution to the summation appears to be:

k * (-i)^n * (i^n - 1) / (i - 1)

Hope that helps, for whatever you are trying to do.

Best,
Guido

I have tried an alternate Time Base, e.g.: Modelyear = TIME BASE( 2000, 1 ) ~ Year ~ | But that will not work also because the Bar Graph is not affected by the chosen time base at all for some reason. It only uses the model's time base which seems to be a bug or at least unfortunate programming. So ...

Unfortunately I fail to see a way to have even a customized bar graph show dates for the x-axis. Is there a way other than setting up the model with a starting time of "2000" and the like?

Guido

Hi Tony, So far I have broken down my - admittedly a bit abstract - original post to the problem of merging the continuous representation of (accounting) flows in SD-models with what a management accountant would expect when that flow is depicted in chart form. To achieve this kind of presentation/c...

A short addendum: I have modified the formula for CAPEX annually reported as follows: CAPEX annually reported = IF THEN ELSE( yearEndedQ, CAPEX per year continuously reported, :NA: ) ~~| This is at least coming closer to what I want but it still is not really pretty, when compared to the Redmond sol...

Hi Tony, I have added a simple model showing Capital Expenditure (CAPEX) for vehicle purchases modeled as pulses. You will also find an (ultimately simple) Bar Graph to show annual data for accounting values done by using that ubiquitous spreadsheet tool from Redmond. In the models' bar graph I have...

Dear Vensim-Support: I am wondering how to customize a Bar Graph using the possibilities of the text based .vgd-files as needed in order to achieve the following: The model will run at a Time Step significantly smaller than some reporting period (e.g. reporting period is a year for annual reporting ...

Hi JJ, unfortunately I have to agree with you there, the choice of name is a bit awkward with an unfortunate proximity to "vanity". So -- if this is still possible -- why not keep the established brand "Vensim" and make it something like: Vensim Hybrid Decision Support (Vensim HD...