topic Re: Improve linear model in Discussions

Improve linear model

LambdaCapybara4 — Mon, 03 Jul 2023 08:58:11 GMT

Hello,

Attached is a Residual by Predicted Plot for some model built on historical data from some process.

When you see such a graph for residuals, what would you recommend to change in the model in order to solve the slope and make residuals be randomly distributed around 0?

Thanks in advance!

Re: Improve linear model

P_Bartell — Mon, 03 Jul 2023 11:54:43 GMT

Can you share the data and model specified that resulted in the residual plot you shared? And some context on the practical problem/issue you are trying to resolve? Lacking these three things it's hard to recommend a next step that would achieve your goal.

Re: Improve linear model

MRB3855 — Mon, 03 Jul 2023 12:14:55 GMT

Hi @LambdaCapybara4 : As @P_Bartell indicated, it is hard to diagnose with the limited information given. That said, my guess would be that your model is missing a predictor.

Re: Improve linear model

Mark_Bailey — Mon, 03 Jul 2023 19:34:20 GMT

I retract the idea of no intercept. I also think it is a strong linear effect missing from the model.

Re: Improve linear model

LambdaCapybara4 — Tue, 04 Jul 2023 08:14:35 GMT

Thank you for you reply

Unfortunately, the data are sensitive and cannot be shared :(

i will try to optimize with all the feedbacks i've got

Re: Improve linear model

LambdaCapybara4 — Tue, 04 Jul 2023 08:35:00 GMT

Just reviewed my Fit Model dialogue window and found out "No Intercept" was checked!

Unchecking it resolved the problem, attached is the resolved Residuals Plot.

Can I ask you how did you know that from this plot? Besides tons of experience, that i guess you have...

And, if you see abnormalities in the attached improved plot, I'd also be glad to know.

Thanks a lot!

Re: Improve linear model

MRB3855 — Tue, 04 Jul 2023 08:48:51 GMT

@LambdaCapybara4 : Good discussion about this here.

https://stats.stackexchange.com/questions/200103/what-can-be-inferred-from-this-residual-plot

Re: Improve linear model

P_Bartell — Tue, 04 Jul 2023 12:33:57 GMT

Understood about the '...sensitive...' nature of your data. Not uncommon. But did you know within the JMP ecosystem there is a pathway to anonymize data that is easy to use and works for many users? It's described here in the JMP documentation: Anonymize Data in JMP