do: Do anything

In hadley/dplyr: A Grammar of Data Manipulation

Do anything

Description

do() is superseded as of dplyr 1.0.0, because its syntax never really felt like it belonged with the rest of dplyr. It's replaced by a combination of reframe() (which can produce multiple rows and multiple columns), nest_by() (which creates a rowwise tibble of nested data), and pick() (which allows you to access the data for the "current" group).

Usage

do(.data, ...)

Arguments

.data	a tbl
...	Expressions to apply to each group. If named, results will be stored in a new column. If unnamed, must return a data frame. You can use . to refer to the current group. You can not mix named and unnamed arguments.

Examples

# do() with unnamed arguments becomes reframe() or summarise()
# . becomes pick()
by_cyl <- mtcars %>% group_by(cyl)
by_cyl %>% do(head(., 2))
# ->
by_cyl %>% reframe(head(pick(everything()), 2))
by_cyl %>% slice_head(n = 2)

# Can refer to variables directly
by_cyl %>% do(mean = mean(.$vs))
# ->
by_cyl %>% summarise(mean = mean(vs))

# do() with named arguments becomes nest_by() + mutate() & list()
models <- by_cyl %>% do(mod = lm(mpg ~ disp, data = .))
# ->
models <- mtcars %>%
  nest_by(cyl) %>%
  mutate(mod = list(lm(mpg ~ disp, data = data)))
models %>% summarise(rsq = summary(mod)$r.squared)

# use broom to turn models into data
models %>% do(data.frame(
  var = names(coef(.$mod)),
  coef(summary(.$mod)))
)

# ->
models %>% reframe(broom::tidy(mod))

hadley/dplyr documentation built on Nov. 6, 2024, 4:48 p.m.