Ventana software support forum

This model maps data import/export options in Vensim. If you open this in Vensim, the blue underlined items are hyperlinks to Help system topics: Here's an image of the model (links won't work):

Few questions: 1) I have historical data on 3 variables from my model on each driver (monthly driving, errors/mile, and errors/month). Can I just import data on 2 variables: errors/mile and monthly driving? Just because the third variable (errors/month) is a product of the other 2 variables. Or is ...

One more link:

https://www.vensim.com/documentation/ref_data.htm

https://www.vensim.com/documentation/in ... s_data.htm
https://www.vensim.com/documentation/usr16.htm

For the moment, you have to calculate the binomial or Poisson likelihood explicitly in an equation. Adding it to the optimizer's builtin distributions is just a convenience.

This conversation spurred me to add Poisson and Binomial distributions to the optimization payoff calculations, so that part will get easier as soon as we release 6.5. In the meantime, I'll post an example ASAP.

For data input, it looks like your data is already in Tidy format, so I'd use that - https://www.vensim.com/documentation/in ... dy2vdf.htm, or GET XLS DATA/GET DIRECT DATA if you want live spreadsheet links.

You might start with averages just to get a quick answer, but I'd lean toward individual stats. For example, if the model reduces to something like the following: error frequency = f ( state of driver ) ~ errors/sec Then the probability of making an error in the next time step is P error = 1-exp(-er...

Either that, or you have more than one virus protection application active, and not all are disabled.

One more thing to think about: The error distribution is probably not Normal (Gaussian). - If drivers make lots of errors, it's probably approximately Normal, in which case you could ignore this. - If they make only a few in total, it's probably Poisson - If you're looking at errors over time, it's ...

In general, there are two distinct situations: - If you have a population of individuals, but you don't have input data for the particular causes of errors for each driver, you probably can't expect to replicate the time series error rate for any particular driver. Therefore comparing individual dri...

Another option would be to use a level to store the time at which the price increase started.

This seems like unrealistic logic for a real firm. Is this for some kind of discrete game decision or something like that?

DELAY FIXED( weight, one day ) would work. There's a sample model for it (and everything else) in the Help system.

Definitely. We have a working prototype, but it's not ready for real use. The main challenge is dealing with detail - a Vensim model with arrays implies a certain entity structure, but discerning what to do at entity boundaries is complex. In many cases, it'll make sense to change the model architec...

Definitely. We'll provide a direct analog as well as something more robust to noise.

There's no great difference on the Vensim side.

Relational is rather verbose (lots of repeated variable names) so I tend to avoid that.

Otherwise, it really depends what your source data looks like - you can generally pick a format that minimizes the transformation needed.

I think the obvious thing to do here would be to make either the interest rate of the stock of domestic money holdings a stock that adjusts in response to pressure. For example, you might have: Actual holdings = INTEG( change in holdings, initial holdings ) change in holdings = (Desired holdings - a...

It's not an internal precision issue; it's that the label is apparently using the integer truncation of whatever the real date is.

126 won't work because 126/6 = 21 months.

144 months with 6 divisions or 132 with 11 divisions should work though.

You have 6 divisions of 11 years here, which is a little unnatural because that means 22 month intervals. However, the labels are misleading, because they don't indicate the lack of precision - those dates should be Oct. 2006, Aug 2008, June 2010, ... I'll see what we can do to improve the display. ...

This model would really benefit from having units defined and balanced. That might reveal the error.

The way to find the answer is to trace the causes of "Proporção de Viagens TP." See for example https://www.vensim.com/documentation/20440.htm or http://vensim.com/causal-tracing-in-vensim/ . You'll find quickly that "Uso Total do TP" goes negative very quickly. There's clearly a...

Can you post the model so we can take a look? If you also have a backup copy, that would be useful for comparison.

That shouldn't be necessary. GET DIRECT should give you a slider whether or not there's a subscript. Example:

I just tested GET XLS and yes, it works that way.

The encryption in Venapp and the redistribution kit will do this, I think. As for Microsoft Office, it's not strong encryption (a dedicated sneak can break it), so deleting the diagrams might be an additional precaution.