with_groups {dplyr}

R Documentation

Perform an operation with temporary groups

Description

This is an experimental new function that allows you to modify the grouping variables for a single operation.

Usage

with_groups(.data, .groups, .f, ...)

Arguments

.data	A data frame
.groups	<tidy-select> One or more variables to group by. Unlike group_by(), you can only group by existing variables, and you can use tidy-select syntax like c(x, y, z) to select multiple variables. Use NULL to temporarily ungroup.
.f	Function to apply to regrouped data. Supports purrr-style ~ syntax
...	Additional arguments passed on to ....

Examples

df <- tibble(g = c(1, 1, 2, 2, 3), x = runif(5))
df %>%
  with_groups(g, mutate, x_mean = mean(x))
df %>%
  with_groups(g, ~ mutate(.x, x1 = first(x)))

df %>%
  group_by(g) %>%
  with_groups(NULL, mutate, x_mean = mean(x))

# NB: grouping can't be restored if you remove the grouping variables
df %>%
  group_by(g) %>%
  with_groups(NULL, mutate, g = NULL)

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