heads: Apply head() across each element in a list of vectors

In jmw86069/jamba: Just Analysis Methods Base

Apply head() across each element in a list of vectors

Description

Apply head() across each element in a list of vectors

Usage

heads(x, n = 6, ...)

Arguments

x	list of atomic vectors, assumed to be the same atomic type.
n	integer maximum number of items to include from each element in the list x. When n contains multiple values, they are recycled to length(x) and applied to each list element in order.
...	additional arguments are passed to utils::head().

Details

Note that this function currently only operates on a list of vectors. This function is notably faster than lapply(x, head, n) because it operates on the entire vector in one step.

Also the input n can be a vector so that each element in the list has a specific number of items returned.

Value

list with at most n elements per vector.

See Also

Other jam list functions: cPaste(), jam_rapply(), list2df(), mergeAllXY(), mixedSorts(), rbindList(), relist_named(), rlengths(), sclass(), sdim(), uniques(), unnestList()

Examples

l <- list(a=1:10, b=2:5, c=NULL, d=1:100);
heads(l, 1);

heads(l, 2);

heads(l, n=c(2, 1, 3, 5))

jmw86069/jamba documentation built on June 9, 2025, 5:52 a.m.