Ventana software support forum

Ok, as Tomfid and Administrator suggested me, I looked at the documentation and the examples so I discovered I have non been clear enough. What I want to do is to load from an Excel file the tabular definition of a function f() and use it as f(x) with x \in [xmin, xmax] before the start of any simul...

Administrator wrote:Not with PLE. You'd need PLE+, Pro or DSS to read the data directly.

Hi Administrator
thanks... so PLE+ is fine.... could you give me some hints? I know a collegue who has that version....
All the best.
Lorenzo

Ok, sorry, I partially solved.. there were some missing , between the )( but the whole process is really boring.. is there any direct way to access the data within an excel file?
L.

Hi to everybody is there any way to use the encolsed excel file as an input for a lookup function in Vensim PLE? With some efforts I translated the data so to get a series of values of the type (a,b),(c,d) but when I tried to copy and paste sush a series within a lookup I found some problems since o...

tomfid wrote:As a workaround, you could add a converter for watts per joule/sec, and use that in places where it's convenient to make the transition.

Hi Tomfid
it's just what I've done but the former solution would be more elegant (IMHO).
All the best.
Lorenzo

tomfid wrote:Afraid not. We should add that. Ventity does it.

Hi Tomfid
it is a nice feature worth being added (IMHO).... thank you a lot anyway.
Lorenzo

Hi
is there any way to say to Vensim to consider W as equivalent to J/Second? I tried to state W,J/Second in the Units Equiv tab under Model Settings but it does not work....
All the best.
Lorenzo (who spends his saturday afternoons modelling... ))

Hi
I was able to solve by using the following relation that guarantees the convergencence of the Taylor series with a limited number of terms that I use to implement the hypergeometric function :
1F1(a,b,z)=exp(z)*1F1(b-a,b,-z)
to be used if z<0.
Anyway, thank you all for your suggestions.
Lorenzo

Why is the behaviour absurd? Because doseAdenovirus increases linearly with time according to doseAdenovirus=ConcentrationAdenovirus*Time*rin*rf/(reff*fconv) and so I expect a strictly monotone behavior from 1F1 and so from Pinf=1-1F1, don't you agree with me? If you do agree you cannot deem the cu...

Hi could you please check the attached model and explain the seemingly absurd behavior of the 1F1 variable through which I'm trying to implement the infinite series expression of such the 1F1 Hypergeometric function? How many terms should I consider? Is there any better and more clever way (in Vens...

Hi could you please check the attached model and explain the seemingly absurd behavior of the 1F1 variable through which I'm trying to implement the infinite series expression of such the 1F1 Hypergeometric function? How many terms should I consider? Is there any better and more clever way (in Vensi...

tomfid wrote:You can indeed apply for a free academic license, which will be granted as long as you meet the criteria.

Hi, thank you and sorry for my delaied answer.. which are the criteria?
All the best.
Lorenzo

Tomfid, sorry No problem. I'm not 100% certain, but the integral breaks up to terms with e^x, xe^x, and x^2e^x, so it should be solvable. The gamma function may be a problem in PLE though. Hi Tomfid I was able to find this nice calculator http://keisan.casio.com/exec/system/1349143651 so I will get...

Ah ... I think the function is just a generalization of the series that appears in the pdf of the distribution. Seems like you should be able to implement the integral representation here, http://mathworld.wolfram.com/ConfluentHypergeometricFunctionoftheFirstKind.html because Vensim has the log Gam...

Ah ... I think the function is just a generalization of the series that appears in the pdf of the distribution. Seems like you should be able to implement the integral representation here, http://mathworld.wolfram.com/ConfluentHypergeometricFunctionoftheFirstKind.html because Vensim has the log Gam...

could you please be more precise? No (I had never heard of the function before you posted today). I found the GNU Scientific Library when searching for 1F1. All I can suggest is downloading the source code and searching it. Ok, thank you a lot.. at the ned I found the code but I'm 99% sure it canno...

Search Google fpr GSL 1F1, this will give you the source code. Try and replicate this in Vensim. I have searched and I've found that the funciotn is implemented through a routine called gsl_sf_hyperg_1F1 but I was able to find only references in pdf files but no source code, could you please be mor...

how to proceed and I'm still waiting Search Google fpr GSL 1F1, this will give you the source code. Try and replicate this in Vensim. I have searched and I've found that the funciotn is implemented through a routine called gsl_sf_hyperg_1F1 but I was able to find only references in pdf files but no...

The difference between the hypergeometric distribution and the binomial distribution is drawing without vs. with replacement. So, as long as the populations N and K are large with respect to the number drawn n, or n = 0 or 1, you can get a close approximation with RANDOM BINOMIAL. This will general...

Administrator wrote:I've already suggested trying to replicate the function using the GSL source files, this is all you can do in PLE.

I remember but you too should remember that I asked you some more details on how to proceed and I'm still waiting...
Lorenzo

Administrator wrote:External functions cannot be implemented in PLE.

Gosh... any shortcut for solving my problem?
Lorenzo

Unfortunately, it looks like the easiest option might be to build an external function to do this (using the GNU Scientific Library). Thank you... unfortunately for me I'm a newbie of programming and have no idea of GNU Scientific Library so it would be very nice of you if you could give me some de...

I found this site
http://keisan.casio.com/exec/system/1349143651
that looks nice. Unfortunately my z parameter is a dose parameter that increases over time depending on a certain number of other parameters and from the running time of my simulations too so I cannot use that tool...
any idea?
Lorenzo

Have you tried to replicate the 1F1 function in Vensim? The source code (in C (GNU Scientific Library)) is available on the internet. Hi I just looked for some definitions and I found out some here http://functions.wolfram.com/HypergeometricFunctions/Hypergeometric1F1/02/ but none, imho, directly r...

No, there is no PLE version of Ventity (but just like Vensim PLE, it is free for educational use at the moment). Ok, I trust you but, after requesting a download, I got an e-mail of a different flavour where I read, after the download link and among other things: "You must connect with the int...