new_grouped_df: Low-level construction and validation for the grouped_df and...

In hadley/dplyr: A Grammar of Data Manipulation

Low-level construction and validation for the grouped_df and rowwise_df classes

Description

new_grouped_df() and new_rowwise_df() are constructors designed to be high-performance so only check types, not values. This means it is the caller's responsibility to create valid values, and hence this is for expert use only.

validate_grouped_df() and validate_rowwise_df() validate the attributes of a grouped_df or a rowwise_df.

Usage

new_grouped_df(x, groups, ..., class = character())

validate_grouped_df(x, check_bounds = FALSE)

new_rowwise_df(data, group_data = NULL, ..., class = character())

validate_rowwise_df(x)

Arguments

x	A data frame
groups	The grouped structure, groups should be a data frame. Its last column should be called .rows and be a list of 1 based integer vectors that all are between 1 and the number of rows of .data.
...	additional attributes
class	additional class, will be prepended to canonical classes.
check_bounds	whether to check all indices for out of bounds problems in grouped_df objects

Examples

# 5 bootstrap samples
tbl <- new_grouped_df(
  tibble(x = rnorm(10)),
  groups = tibble(".rows" := replicate(5, sample(1:10, replace = TRUE), simplify = FALSE))
)
# mean of each bootstrap sample
summarise(tbl, x = mean(x))

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