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Feb 6, 2021 at 0:46 vote accept rnorouzian
Feb 5, 2021 at 18:13 answer added Livius timeline score: 3
Feb 5, 2021 at 15:24 comment added Livius In all these cases, it would also be helpful to know something about the structure of the data -- what are the properties of each of the data variables? Are some of them bounded? Are some categorical? Etc.
Feb 5, 2021 at 15:22 comment added Livius Related to my previous comment on the XY Problem: what type of equivalence are you going for? Equivalent predictions? Then test the fitted values and predicted values on a hold-out set. Identical model matrices? Test those directly, although floating point error and differences in estimation between the functions may lead to some differences. One-to-one correspondence between coefficients in two different ways of expressing a model formula? Convert the first formula to math notation, do some algebra to get it into a form that lends itself to conversion to Wilkinson notation for linear models.
Feb 5, 2021 at 15:15 comment added Livius Even if this isn't homework, I still would like to see some explanation about how and why you converted from nlme to lme. How: what steps did you take to reformulate the problem. Why: why do you need to rewrite an nlme model as an lme model? Without some motivation, this seems like an XY Problem. If the motivation is understanding the conversion, then some of the derivation in your proposed conversion needs to be shown.
Feb 5, 2021 at 1:43 comment added Livius This feels like a homework question and looking at the repo with the data, it seems like a homework question. It should be tagged self-study.
Feb 5, 2021 at 1:42 review Suggested edits
Feb 5, 2021 at 2:47
Feb 4, 2021 at 5:37 history edited rnorouzian CC BY-SA 4.0
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Feb 4, 2021 at 4:48 comment added Jeremy Miles I don't know enough about nlme to answer, but I reformatted the code to make it easier (for me) to read, and added the AIC, which is very similar for the two models - not sure if that means something. :)
Feb 4, 2021 at 4:47 history edited Jeremy Miles CC BY-SA 4.0
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Feb 4, 2021 at 3:13 history edited rnorouzian CC BY-SA 4.0
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Feb 4, 2021 at 0:48 history asked rnorouzian CC BY-SA 4.0