merging rows and taking average of duplicate rows rstudio
library(data.table)
dat <- read.table(text='name value etc1 etc2
A 9 1 X
A 10 1 X
A 11 1 X
B 2 1 Y
C 40 1 Y
C 50 1 Y',header=TRUE)
keys <- colnames(dat)[!grepl('value',colnames(dat))]
X <- as.data.table(dat)
X[,list(mm= mean(value)),keys]
name etc1 etc2 mm
1: A 1 X 10
2: B 1 Y 2
3: C 1 Y 45