I am working on a dataset which has multiple species over several plots, categorised into two treatment groups.
For example group_xy group_op plot species value x o 1 A 3 x o 1 A 5 x o 1 B 4 x o 2 A 3 x o 2 A 6 x o 2 A 3 y o 1 A 3 y o 1 A 5 y o 1 B 4 y o 2 A 3 y o 2 A 6 y o 2 A 3 x p 1 A 3 x p 1 A 5 x p 1 B 4 x p 2 A 3 x p 2 A 6 x p 2 A 3 y p 1 A 3 y p 1 A 5 y p 1 B 4 y p 2 A 3 y p 2 A 6 y p 2 A 3 What I would like to do is to take the mean of the species within each plot in each treatment group, then generate the mean for the species based upon the average of the values between plots. Thus the intermediate output would be group_xy group_op plot species mean_value standard_deviation x o 1 A 3 sd x o 1 B 4 sd x o 2 A 4 sd y o 1 A 3 sd y o 1 B 4 sd y o 2 A 4 sd x p 1 A 3 sd x p 1 B 4 sd x p 2 A 4 sd y p 1 A 3 sd y p 1 B 4 sd y p 2 A 4 sd Then eventually group_xy group_op species total_mean_value standard_deviation x o A 3.5 sd x o B 4 sd y o A 3.5 sd y o B 4 sd x p A 3.5 sd x p B 4 sd y p A 3.5 sd y p B 4 sd I am looking for an elegant code which would allow me to do this and generate plots. for all species for all treatment groups. Any help would be appreciated! [[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.