Hi [EMAIL PROTECTED] napsal dne 04.08.2007 07:49:16:
> Well, R has a by() function that does what you want, and its help page > contains an example of doing regression by group. > > (There are other ways.) E.g. you can split your data into list d.s <- split(data, data$site) and then use lapply to perform your task on all parts of this list result <- lapply(d.s, function) Regards Petr > > On Fri, 3 Aug 2007, Paul Young wrote: > > > So I am trying to perform a robust regression (fastmcd in the robust > > package) on a dataset and I want to perform individual regressions based > > fastmcd does not do regression ... or I would have adapted the ?by > example to show you. > > > on the groups within the data. We have over 300 sites and we want to > > perform a regression based on the day of week and the hour for every > > site. I was wondering if anyone knows of a "'by' command similar to the > > one used in SAS that automatically groups the data for the regressions. > > If not, does anyone have any tips on how to split the data into smaller > > sets and then perform the regression on each set. I am new to R, so I > > don't know all of the common work arounds and such. At the moment the > > only method I can think of is to split the data using condition > > statements and manually running the regression on each set. Thanks or > > your help > > > > -Paul > > > -- > Brian D. Ripley, [EMAIL PROTECTED] > Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ > University of Oxford, Tel: +44 1865 272861 (self) > 1 South Parks Road, +44 1865 272866 (PA) > Oxford OX1 3TG, UK Fax: +44 1865 272595 > > ______________________________________________ > R-help@stat.math.ethz.ch 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@stat.math.ethz.ch 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.
