with_groups: Perform an operation with temporary groups

In poorman: A Poor Man's Dependency Free Recreation of 'dplyr'

Perform an operation with temporary groups

Description

This function allows you to modify the grouping variables for a single operation.

Usage

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

Arguments

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

Examples

df <- data.frame(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, x_mean = mean(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)

poorman documentation built on Nov. 2, 2023, 5:27 p.m.