Can I use LOOKUP SLOPE to access point to point slopes as rate data?

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tc20852
Junior Member
Posts: 17
Joined: Tue Jan 12, 2021 4:22 am
Vensim version: PRO

Can I use LOOKUP SLOPE to access point to point slopes as rate data?

Post by tc20852 »

Hello Everyone,

Here are some Kinetics based data input as a lookup "RawDataLookupTable".

the problem is that point to point slopes must be available as input for a rate between two stocks in a larger model. See png of the graph of the output to "gradients" that I am trying to achieve.

I've tried using LOOKUP SLOPE but this is not giving me what I want. See screenshot of an excel graph.

Thoughts anyone?

Thomas
Attachments
pointToPointGradientsExcel.PNG
pointToPointGradientsExcel.PNG (27.57 KiB) Viewed 1276 times
TestPointToPointCurveInput.mdl
(1.81 KiB) Downloaded 126 times
tomfid
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Joined: Wed May 24, 2006 4:54 am

Re: Can I use LOOKUP SLOPE to access point to point slopes as rate data?

Post by tomfid »

I think the reason you're not seeing what you expect is that your model time step is 1, so you aren't evaluating any points that are in between the data points.

Make time step << 1 and you'll see something like the gray line.
tc20852
Junior Member
Posts: 17
Joined: Tue Jan 12, 2021 4:22 am
Vensim version: PRO

Re: Can I use LOOKUP SLOPE to access point to point slopes as rate data?

Post by tc20852 »

Oh, I had to restart vensim. When I went back to look at my original problem, the lookup slope worked great.
see attached.
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secondTest.mdl
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tomfid
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Re: Can I use LOOKUP SLOPE to access point to point slopes as rate data?

Post by tomfid »

I think the key difference here is that time step = .015625.
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