lapply {base}

R Documentation

Apply a Function Over a List

Description

lapply returns a list of the same length as x. Each element of which is the result of applying fun to the corresponding element of x.

sapply is a “user-friendly” version of lapply also accepting vectors as x, and returning a vector or array with dimnames if appropriate.

Usage

lapply(x, fun, ...)
sapply(x, fun, ..., simplify = TRUE)

Arguments

x	list (or vector for sapply) to be used.
fun	the function to be applied. In the case of functions like +, %*%, etc., the function name must be quoted.
...	optional arguments to fun.
simplify	logical; should the result be simplified to a vector if possible?

See Also

apply, tapply.

Examples

x <- list(a = 1:10, beta = exp(-3:3), logic = c(T,F,F,T))
# compute the list mean for each list element
lapply(x,mean)
# median and quartiles for each list element
lapply(x, quantile, probs = 1:3/4)
sapply(x, quantile)
sapply(sapply(3:9, seq), fivenum)

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