table.express (version 0.4.2)

mutate-table.express: Add or update columns

Description

Add or update columns of a data.table::data.table, possibly by reference using :=.

Usage

# S3 method for ExprBuilder
mutate(
  .data,
  ...,
  .sequential = FALSE,
  .unquote_names = TRUE,
  .parse = getOption("table.express.parse", FALSE),
  .chain = getOption("table.express.chain", TRUE)
)
# S3 method for EagerExprBuilder
mutate(.data, ..., .parent_env = rlang::caller_env())
# S3 method for data.table
mutate(.data, ...)

Arguments

.data

An instance of ExprBuilder.

...

Mutation clauses.

.sequential

If TRUE, each expression in ... is assigned to a nested body within curly braces to allow them to use variables created by previous expressions. The default is FALSE because enabling this may turn off some data.table optimizations.

.unquote_names

Passed to rlang::enexprs(). Set to FALSE if you want to pass the single := expression.

.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?

.parent_env

See end_expr()

Details

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

Examples

data("mtcars")
data.table::as.data.table(mtcars) %>%
    start_expr %>%
    mutate(mpg_squared = mpg ^ 2)