更新时间:2023-12-01 11:57:52
如果我正确理解,则可以执行以下操作:
If I understand correctly, you could do the following:
df1[, paste(col_needed, "R", sep = "_") :=
Map(function(x,y) mean(get(x), na.rm = TRUE)/mean(get(y), na.rm=TRUE),
col_needed,
paste(col_needed, "PAN", sep = "_")),
by=region]