How to replace NA with mean by group / subset?
Not my own technique I saw it on the boards a while back: dat <- read.table(text = “id taxa length width 101 collembola 2.1 0.9 102 mite 0.9 0.7 103 mite 1.1 0.8 104 collembola NA NA 105 collembola 1.5 0.5 106 mite NA NA”, header=TRUE) library(plyr) impute.mean <- function(x) replace(x, is.na(x), mean(x, na.rm = … Read more