Hi r-help-boun...@r-project.org napsal dne 04.11.2010 13:28:06:
> > Hello, > > I have tried to find this out some other way, but unsuccessful I have to > try this list. > I assume this should be quite simple. > > I have a dataset with 4 columns, "Sample_no", "Species", "Nitrogen", > "Carbon" in csv format. In the species column I have many different > species with varying number of obs per species > > Eg > > "Sample_no" "Species" "Nitrogen" "Carbon" > 1 Cod 15.2 -19.0 > 2 Haddock 14.8 -20.2 > 3 Cod 15.6 -18.5 > 4 Cod 13.2 -20.1 > 5 Haddock 14.3 -18.8 > Etc.. > > And I want to calculate, mean, standard dev etc per species for the > observations "Nitrogen" and "Carbon". And later do plots and stats with > the different species. I will in the end have many species, so need it to > be "automatic" I can't enter code for every species separate. No need for sorting. You can us R. Particularly ?tapply, ?by or ?aggregate commands. Regarding plots you can consider lattice or ggplot2, but you can get good results also with base graphics. aggregate(your.data[,3:4], list(yourdata$Species), function(x) c(mean(x), sd(x))) xyplot(nitrogen~carbon|species, data=your.data) Regards Petr > > Can anyone help me with this? Or if this is the wrong list to sendt this > question to, where do I send it? > > Thank you very much in advance. > > > Best regards > > Silje Ramsvatn > > PhD-candidate > University of Tromsø > Norway > > ______________________________________________ > 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.
