key_by: Set key to group by

In table.express: Build 'data.table' Expressions with Data Manipulation Verbs

Set key to group by

Description

Group by setting key of the input.

Usage

key_by(.data, ...)

## S3 method for class 'ExprBuilder'
key_by(
  .data,
  ...,
  .parse = getOption("table.express.parse", FALSE),
  .chain = getOption("table.express.chain", TRUE)
)

## S3 method for class 'data.table'
key_by(.data, ...)

Arguments

.data	Object to be grouped and subsequently keyed.
...	Arguments for the specific methods.
.parse	Logical. Whether to apply rlang::parse_expr() to obtain the expressions.
.chain	Logical. Should a new frame be automatically chained to the expression if the clause being set already exists?

Details

Everything in ... will be wrapped in a call to list. Its contents work like Clauses for grouping on columns. The keyby inside the data.table::data.table frame.

To see more examples, check the vignette, or the table.express-package entry.

Examples

data("mtcars")

data.table::as.data.table(mtcars) %>%
    start_expr %>%
    key_by(cyl, gear)

table.express documentation built on April 3, 2023, 5:43 p.m.