[R] How to check a regression model's fit?

[Jeff Newmiller]

Many ways... but they all assume you know the background theory, which you 
don't seem to, and which is off-topic here.

Consider reading some help files:

?summary.lm
?plot.lm

Re: regression not existing... the classic case is when your data fit your 
model too perfectly... regression must have some nonzero error in your 
data to work.  (That is a bonus bit of theory to get you started.)
In most real-world cases, you are more likely to encounter a situation 
where your proposed regression model is simply inappropriate for your 
data, and the regression algorithm plows along successfully computing 
garbage.

On Tue, 3 Feb 2015, TMF wrote:

> as the title says (from an R begginer). Is it also possible that regression,
> in a given data's case, just doesn't exist -- for any type of applied
> regression modelling?
>
> Thanks!
>
> --
> View this message in context: http://r.789695.n4.nabble.com/How-to-check-a-regression-model-s-fit-tp4702766.html
> Sent from the R help mailing list archive at Nabble.com.

Note that Nabble is _not_ the R-help mailing list archive, despite its 
claims.

> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

The above text may not make it to you... which is why Nabble is not the 
R-help mailing list archive.

---------------------------------------------------------------------------
Jeff Newmiller                        The     .....       .....  Go Live...
DCN:<jdnewmil at dcn.davis.ca.us>        Basics: ##.#.       ##.#.  Live Go...
                                       Live:   OO#.. Dead: OO#..  Playing
Research Engineer (Solar/Batteries            O.O#.       #.O#.  with
/Software/Embedded Controllers)               .OO#.       .OO#.  rocks...1k