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
Misterious Calculation not computed
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Re: Misterious Calculation not computed
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.
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Re: Misterious Calculation not computed
A possible test would be to compute SUM(Alfa[Sub!]) in a separate variable.
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Re: Misterious Calculation not computed
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?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.
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Re: Misterious Calculation not computed
You can email it to us at vensim@vensim.com. Please ensure that you include your licence details.
Advice to posters seeking help (it really helps us to help you)
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http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391
Units are important!
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