Dear Vensim Forum Members,
I am reaching out to seek assistance with a problem I encountered while conducting a Monte Carlo sensitivity analysis on my model.
To provide some context, I have constructed a deterministic model aimed at analyzing water demand within a specific area. To introduce stochasticity and uncertainty into the simulation, I have defined some input variables to follow probability distributions using random functions (I calculated the parameter of the random function with R and then added it to my Vensim model). To observe how the values of these random variables fluctuate across different simulations, I opted for a multivariate sensitivity analysis.
Specifically, I selected one of my random variables ('Population', described through a random Weibull) and asked Vensim to perform a sensitivity analysis with a random Weibull distribution. I started with a low number of simulations, precisely 2, focusing on just one variable from the list ('drinking water demand'). However, upon running the analysis, Vensim returned an error message which I have included below. I am struggling to identify the root cause of this issue. Could it be related to the fact that the variable I selected for sensitivity analysis is already a random function? Or perhaps it is a matter of model complexity? Could it have something to do with the fact that my model works with different subscripts?
I would greatly appreciate any insights or guidance you can offer to help me troubleshoot and resolve this issue. Thank you very much for your time and assistance.
Best regards,
Virginia
Issue with Monte Carlo Sensitivity Analysis in Vensim
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- Junior Member
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Issue with Monte Carlo Sensitivity Analysis in Vensim
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- Super Administrator
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Re: Issue with Monte Carlo Sensitivity Analysis in Vensim
Can you upload the model and associated files so we can try and run the same thing?
What version of Vensim are you using?
What version of Vensim are you using?
Advice to posters seeking help (it really helps us to help you)
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391
Units are important!
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http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391
Units are important!
http://www.bbc.co.uk/news/magazine-27509559
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- Junior Member
- Posts: 2
- Joined: Sat May 06, 2023 9:47 am
- Vensim version: DSS
Re: Issue with Monte Carlo Sensitivity Analysis in Vensim
Could I send the model internally? I cannot show it publicly. I have restrictions on this
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- Super Administrator
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Re: Issue with Monte Carlo Sensitivity Analysis in Vensim
Please do, vensim@vensim.com. Please ensure you include your licence details.
Advice to posters seeking help (it really helps us to help you)
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391
Units are important!
http://www.bbc.co.uk/news/magazine-27509559
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391
Units are important!
http://www.bbc.co.uk/news/magazine-27509559