Noise Seed in Venapp

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Hossein
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Posts: 48
Joined: Thu Sep 15, 2016 7:50 am
Vensim version: DSS

Noise Seed in Venapp

Post by Hossein »

Dear Tom, Dear Administrator,

I would like to put a variable in my Venapp, that the user can change the Noise Seed and/or Number of Simulation before any sensitivity run. I was looking in Vensim parameters but there is not a Noise Seed and Number of Simulation (like INITIAL TIME) that can be changed through Venapp. Is it any possibility that I can do so?

BR,
Hossein
tomfid
Administrator
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Joined: Wed May 24, 2006 4:54 am

Re: Noise Seed in Venapp

Post by tomfid »

Add NOISE SEED to the model and change it with SETVAL.
https://www.vensim.com/documentation/noise_seed.htm
Hossein
Member
Posts: 48
Joined: Thu Sep 15, 2016 7:50 am
Vensim version: DSS

Re: Noise Seed in Venapp

Post by Hossein »

Dear Tom,

but the problem is that the "Noise Seed" can be changed in the "Sensitivity Simulation Setup" window in Vensim as well as "Number of simulations". But in the Venapp, how should I connect my defined variable to Nose seed? Because in the Venapp, it is not possible to open the "Sensitivity Simulation Setup" window and make the changes! I would appreciate it if you could provide an example.

BR,
Hossein
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Re: Noise Seed in Venapp

Post by Administrator »

Add a constant to the model called "NOISE SEED". You can now change this using SIMULATE>SETVAL. This overrides the value in the sensitivity setup window.
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tomfid
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Re: Noise Seed in Venapp

Post by tomfid »

Hossein is correct - the sensitivity seed can't be changed programmatically. We should change that.

A workaround is to provide several different vsc files with different seeds. Another possibility is to use the vsc file to vary noise seed, and generate the distributions for the target variables inside the model, using the regular RANDOM functions.
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