Ventana software support forum

I find that I cannot have the name run as 'Ratio of scrapped car = 0' and 'Ratio of scrapped car = 0.5' at the same time (I want to do extreme condition test). Specifically, the run including '0.5' will be automatically converted to '0' and the actual '0' run is replaced. How to resolve the issue? T...

I am trying to solve the unit errors with such variables (I attached the model to this question).
How can I solve the errors I have 2 erros as the picture attached.
Thank you.

Can you detail exactly what you do please? Do you click File->Open, or double click in Windows explorer or something else? Also are you running Windows or a Mac with a Windows emulator? I am using Windows. I double click on the model (mdl file) I created before (store in Drive D). Usually, this err...

Administrator wrote: ↑Sun Feb 18, 2024 4:41 pm You can see the new/old GUIs at
viewtopic.php?t=7986

I have checked the GUI as your guidance and find that I am using the new GUI.
However the error still happens everytime when I open the model.
Is there any other reason related to this error?

Administrator wrote: ↑Sun Feb 18, 2024 4:41 pm You can see the new/old GUIs at
viewtopic.php?t=7986

Thank you

Vensim. Program. Error. Yes, using the old GUI. I moved to the new GUI and the problem resolved. While I appreciate the challenge of keeping both GUIs alive, I do have 20+ years of teaching materials in the old format. It's going to be a while before I convert, if at all. Thanks for the pointer. I ...

"Formerly collected" goes to value of approximately 2000. "Informally collected" then goes negative which is one of the causes of the problems. Things quickly go exponential and so you get values that are too large to be stored by the computer, that causes the floating point err...

I have had a floating point error with the model. I tried to fix it but it doesnt work. I appear not to understand this kind of error well. Then I upload the model for your support. Please help me to fix it. Thank you.

Administrator wrote: ↑Wed Sep 13, 2023 1:30 pm Is it a linear increase or stepped?

It is stepped, thank you. How should I do with the functions?

I want to create a function respresenting the following situation:
- The current subsidy is 100 USD
- This subsidy will be increased at a rate of 50% every 5 years?
What should I do?

I am very grateful to your support, thank you.

Thank you so much

I have a question: Can I use TREND function to express a steady decrease of a varibale over time. For example, I have a fraction variable of 0.8 per year. I want to decrease the value of this fraction variable over time at a rate of 0.5% each year within 10 years, for example. Can I use TREND functi...

Just create a separate variable. z = x + y y = WITH LOOKUP(...) Thank you. I am trying to re-establish the model found from a published paper to understand the methodology. The authors explained a formula in which x = a + WITH LOOKUP (y). Then I tried doing similar things but now I know WITH LOOKUP...

tomfid wrote: ↑Mon Feb 06, 2023 3:08 pm Or use an ordinary lookup variable instead of WITH LOOKUP:

z = x + y( input )
y = (0,1),(1,2),(3,4), ...

Thank you

I think the error message may be misleading. WITH LOOKUP has to be the first & only thing on the right side of the equation - that's probably the issue here. Thank you so much, I understood the issue here. What other function can I use in case I want to calculate the total cost as equal to tran...

Could you tell me if there is any error related to missed parens in the following equation? I tried but could not fix it. Thank you. Cost of waste recycling = Transportation cost+WITH LOOKUP(maturation of waste recycling market, ((0.15,40),(0.2,35),(0.3,30),(0.4,27),(0.5,23),(0.6,18),(0.7,16),(0.8,1...

Are you on Mac or Windows? I'm writing this on a Mac so the modifier keys (shift/command) will be different on Windows. To get a multi-segment pipe, you need to hold down SHIFT when drawing the pipe and clicking. Hold COMMAND when you click to set the position of the valve. I am on Windows. Thank y...

I am practicing with the very first steps of Vensim. I am trying with the model Project Dynamics in the part of Vensim modeling guide. Eventhough I followed the structure of making additional pipes I still could not produce the same diagram as described in the guidance. I attached two pictures for y...