Hi tomfid,
sorry for coming back to this issue. I've tried to fix the lookup and also reread the help on lookups as well as the video on lookups (https://vensim.com/lookups-in-vensim/), however I am still lost here.
I simply want to return the value of the lookup with the input time and use it in my flow variable "change in FIT".
Would you mind just fixing it quickly in the model so I can see how to use lookups with time inputs in the rest of my model? (I am using Vensim PLE)
That would be so helpful!
Thanks!
Uploading Data onto Vensim PLE
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Re: Uploading Data onto Vensim PLE
Lookups are really easy to use.
This lookup has values from 2010 until 2040
Lookup table ( (2010,1),(2020,2),(2030,3),(2040,4) )
And to retrieve the value at "time",
looked up value = lookup table ( time )
This lookup has values from 2010 until 2040
Lookup table ( (2010,1),(2020,2),(2030,3),(2040,4) )
And to retrieve the value at "time",
looked up value = lookup table ( time )
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
Re: Uploading Data onto Vensim PLE
I'm on the road and can't modify the model, plus I don't have the data. But the structure you already have for "fit degression rate" is exactly what you need. "FIT degression rate DATA" is the lookup and "FIT degression rate" is the value looked up from the data, by time.
/*
Advice to posters (it really helps us to help you)
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391
Blog: http://blog.metasd.com
Model library: http://models.metasd.com
Bookmarks: http://delicious.com/tomfid/SystemDynamics
*/
Advice to posters (it really helps us to help you)
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391
Blog: http://blog.metasd.com
Model library: http://models.metasd.com
Bookmarks: http://delicious.com/tomfid/SystemDynamics
*/