R: Select and rename a selection of variables

select_all {dplyr}

R Documentation

Select and rename a selection of variables

Description

These scoped variants of select() and rename() operate on a selection of variables. The semantics of these verbs have subtle but important differences:

Selection drops variables that are not in the selection while renaming retains them.
The renaming function is optional for selection but not for renaming.

The _if and _at variants always retain grouping variables for grouped data frames.

Usage

select_all(.tbl, .funs = list(), ...)

rename_all(.tbl, .funs = list(), ...)

select_if(.tbl, .predicate, .funs = list(), ...)

rename_if(.tbl, .predicate, .funs = list(), ...)

select_at(.tbl, .vars, .funs = list(), ...)

rename_at(.tbl, .vars, .funs = list(), ...)

Arguments

`.tbl`	A `tbl` object.
`.funs`	A single expression quoted with `funs()` or within a quosure, a string naming a function, or a function.
`...`	Additional arguments for the function calls in `.funs`. These are evaluated only once, with tidy dots support.
`.predicate`	A predicate function to be applied to the columns or a logical vector. The variables for which `.predicate` is or returns `TRUE` are selected. This argument is passed to `rlang::as_function()` and thus supports quosure-style lambda functions and strings representing function names.
`.vars`	A list of columns generated by `vars()`, a character vector of column names, a numeric vector of column positions, or `NULL`.

Examples

# Supply a renaming function:
select_all(mtcars, toupper)
select_all(mtcars, "toupper")
select_all(mtcars, funs(toupper(.)))

# Selection drops unselected variables:
is_whole <- function(x) all(floor(x) == x)
select_if(mtcars, is_whole, toupper)

# But renaming retains them:
rename_if(mtcars, is_whole, toupper)

# The renaming function is optional for selection:
select_if(mtcars, is_whole)

[Package dplyr version 0.7.6 Index]