R: Extracts a named element from a list of lists.

extractSubList {BBmisc}

R Documentation

Extracts a named element from a list of lists.

Extracts a named element from a list of lists.

extractSubList(xs, element, element.value, simplify = TRUE,
  use.names = TRUE)

`xs`	[`list`] A list of named lists.
`element`	[`character`] Name of element(s) to extract from the list elements of `xs`. What happens is this: `x$el1$el2....`.
`element.value`	[any] If given, `vapply` is used and this argument is passed to `FUN.VALUE`. Note that even for repeated indexing (if length(element) > 1) you only pass one value here which refers to the data type of the final result.
`simplify`	[`logical(1)` \| character(1)] If `FALSE` `lapply` is used, otherwise `sapply`. If “cols”, we expect the elements to be vectors of the same length and they are arranged as the columns of the resulting matrix. If “rows”, likewise, but rows of the resulting matrix. Default is `TRUE`.
`use.names`	[`logical(1)`] If `TRUE` and `xs` is named, the result is named as `xs`, otherwise the result is unnamed. Default is `TRUE`.

[list | simplified vector | matrix]. See above.

xs = list(list(a = 1, b = 2), list(a = 5, b = 7))
extractSubList(xs, "a")

## [1] 1 5

extractSubList(xs, "a", simplify = FALSE)

## [[1]]
## [1] 1
## 
## [[2]]
## [1] 5

[Package BBmisc version 1.7 Index]