Ventana software support forum

We are implementing a model and attempting the first runs. The model fails immediately for a floating point. We are not surprised, however checking for the reasons of the floating point we came across a behaviour of the model we never experienced before.
The floating point is due to a non-computed value (“- -“ in result table) which, in turn depends on a previous non-computed value. Surprisingly for us, the causes of this non-computed value are instead normally computed. Basically: we have a variable Alfa[sub] with six non zero values, then we have an equation
Beta = Alfa[Sub6]/SUM(Alfa[Sub!])
But this equation does not compute anything. Even computing numerator and denominator in separate equations (and numerator is a simple identity…) they do not provide any value despite values of Alfa[Sub] do exist for each subscript.
We have been working in Vensim for years but never seen something similar. Any idea of a possible reason for this behaviour?

Thanks in advance

Can you upload the model so we can take a look? I could put together a test model, but it might not be the same as the one you are having trouble with.

A possible test would be to compute SUM(Alfa[Sub!]) in a separate variable.

Administrator wrote: ↑Tue Dec 17, 2019 4:43 pm Can you upload the model so we can take a look? I could put together a test model, but it might not be the same as the one you are having trouble with.

Thanks for the fast response. Due to the model's complexity we would be glad to send the model, can you indicate how to proceed?

You can email it to us at vensim@vensim.com. Please ensure that you include your licence details.