Hi Ross, the trick is especially split() and unsplit(). Split() splits up the dataframe based on the combined factors, unsplit() transforms it to a dataframe again. This way you can do the calculation for a set of mini-dataframes that contain only the information for 1 combination of the factors.
lapply is the apply-function specifically for lists. As split() gives you a list of dataframes, lapply loops through those dataframes the appropriate way. You can see that for yourself by doing str(seal_list). Hope this clears things out a bit. Cheers Joris On Wed, Jun 2, 2010 at 9:55 AM, RCulloch <ross.cull...@dur.ac.uk> wrote: > > Hi Jorvis, > > Many thanks for sorting that! I haven't seen it done that way before, so > I'll have to look in to the properties of lapply a bit more to get a full > appreciation of other approaches to looping data in R. > > Thanks again for your help, it is much appreciated, > > Ross > -- > View this message in context: > http://r.789695.n4.nabble.com/storing-output-data-from-a-loop-that-has-varying-row-numbers-tp2238396p2239711.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. > -- Joris Meys Statistical Consultant Ghent University Faculty of Bioscience Engineering Department of Applied mathematics, biometrics and process control Coupure Links 653 B-9000 Gent tel : +32 9 264 59 87 joris.m...@ugent.be ------------------------------- Disclaimer : http://helpdesk.ugent.be/e-maildisclaimer.php [[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.
