Operate on a selection of variables

The variants suffixed with _if, _at or _all apply an expression (sometimes several) to all variables within a specified subset. This subset can contain all variables (_all variants), a vars() selection (_at variants), or variables selected with a predicate (_if variants).

Arguments

.tbl	A tbl object.
.funs	List of function calls generated by funs(), or a character vector of function names, or simply a function. Bare formulas are passed to rlang::as_function() to create purrr-style lambda functions. Note that these lambda prevent hybrid evaluation from happening and it is thus more efficient to supply functions like mean() directly rather than in a lambda-formula.
.vars	A list of columns generated by vars(), or a character vector of column names, or a numeric vector of column positions.
.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.
...	Additional arguments for the function calls in .funs. These are evaluated only once, with explicit splicing.

Details

The verbs with scoped variants are:

• mutate(), transmute() and summarise(). See summarise_all().

• filter(). See filter_all().

• group_by(). See group_by_all().

• rename() and select(). See select_all().

• arrange(). See arrange_all()

There are three kinds of scoped variants. They differ in the scope of the variable selection on which operations are applied:

• Verbs suffixed with _all() apply an operation on all variables.

• Verbs suffixed with _at() apply an operation on a subset of variables specified with the quoting function vars(). This quoting function accepts select_vars() helpers like starts_with(). Instead of a vars() selection, you can also supply an integerish vector of column positions or a character vector of column names.

• Verbs suffixed with _if() apply an operation on the subset of variables for which a predicate function returns TRUE. Instead of a predicate function, you can also supply a logical vector.