Fungsi oleh adalah pembungkus berorientasi objek untuk tapply yang diterapkan pada bingkai data.
by(data, INDICES, FUN, …, simplify = TRUE)| Parameter | Deskripsi |
|---|---|
data |
an R object, normally a data frame, possibly a matrix. |
INDICES |
a factor or a list of factors, each of length nrow(data). |
FUN |
a function to be applied to (usually data-frame) subsets of data. |
… |
further arguments to FUN. |
simplify |
logical: see tapply. |
# NOT RUN {
require(stats)
by(warpbreaks[, 1:2], warpbreaks[,"tension"], summary)
by(warpbreaks[, 1], warpbreaks[, -1], summary)
by(warpbreaks, warpbreaks[,"tension"],
function(x) lm(breaks ~ wool, data = x))
## now suppose we want to extract the coefficients by group
tmp <- with(warpbreaks,
by(warpbreaks, tension,
function(x) lm(breaks ~ wool, data = x)))
sapply(tmp, coef)
# }