Hi: On Tue, Jan 25, 2011 at 10:36 AM, Greg Snow <greg.s...@imail.org> wrote:
> It is not clear what you are doing or why you are doing it. If you tell us > your ultimate goal we may be able to help you find a way that does not > require all the computing that you are doing. > > How do you get your coefficients? Are you using lm? Have you looked at the > resid function? > Thanks, Greg. I totally agree that a clearer explanation of the goals of this computing problem would be (very) useful. R has a number of ways to process subsets of data efficiently. One approach (although not unique) would be to (a) split the data into multiple subgroups; (b) run a lm() model in each subgroup; (c) export the model objects to a list; (d) extract the pieces of the output you want for all models run. Several examples of how to do this with enhanced apply-like functions in the plyr package are in the list archives, so this can be done with a bit of thinking and an understanding of what is wanted/needed...especially if you will need to do multiple sets of extractions from your set of model objects. If you find yourself doing the same thing over and over in R, you can bet there's a much more efficient way to do the computations. An explanation of the goals, a subset of data that illustrates the problem (preferably in dput() form) and showing what you've tried would be useful. Dennis > > -- > Gregory (Greg) L. Snow Ph.D. > Statistical Data Center > Intermountain Healthcare > greg.s...@imail.org > 801.408.8111 > > > > -----Original Message----- > > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > > project.org] On Behalf Of Brian J Mingus > > Sent: Tuesday, January 25, 2011 9:08 AM > > To: R-help@r-project.org > > Subject: [R] Extracting SSE from lm > > > > Apologies for this simple question - > > > > Given the number of comparisons I need to do it has become somewhat > > laborious to compute the SSE manually. I first have to extract the > > coefficients, build the model and run the model on the data. So far I > > haven't found any method in R that will do this for me. Is there a > > method > > that I haven't seen, or is there a small function I could write that > > would > > do this, and how might I go about that? > > > > Thanks, > > > > Brian > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help@r-project.org mailing list > > 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. > > ______________________________________________ > R-help@r-project.org mailing list > 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list 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.
