On Feb 14, 2019, at 9:31 AM, Isaac Barnhart <i...@ksu.edu> wrote: > > I am having trouble finding the mean of a specific part of my dataset. Here > is a sample of it: > > plot lai leaf > 1 104 82 1 > 2 104 167 2 > 3 104 248 3 > 4 104 343 4 > 5 104 377 5 > 6 105 64 1 > 7 105 139 2 > 8 105 211 3 > 9 105 296 4 > 10 105 348 5 > 11 106 94 1 > 12 106 167 2 > 13 106 243 3 > 14 106 281 4 > 15 106 332 5 > 16 108 83 1 > 17 108 382 2 > 18 108 320 3 > 19 108 146 4 > 20 108 129 5 > > I have many different plot numbers, none of which follow any kind of specific > numeric sequence (even though I have sorted them from smallest to largest). I > need to take the average (mean) of the LAI for each plot, and was wondering > if there was a way to specify the code to do this. For example: I need the > average of all the LAI measurements for each leaf of plot 104, 105, etc. Any > help would be appreciated. Thanks!
Hi, This is easy using base R functions. See ?aggregate, ?by and ?tapply for a starting place. For example: > aggregate(lai ~ plot, data = DF, FUN = mean) plot lai 1 104 243.4 2 105 211.6 3 106 223.4 4 108 212.0 Regards, Marc Schwartz ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
