nest_nest_join {nplyr}

Nested nest join

Description

nest_nest_join() returns all rows and columns in .nest_data with a new nested-df column that contains all matches from y. When there is no match, the list contains a 0-row tibble.

Usage

nest_nest_join(
  .data,
  .nest_data,
  y,
  by = NULL,
  copy = FALSE,
  keep = FALSE,
  name = NULL,
  ...
)

Arguments

.data

A data frame, data frame extension (e.g., a tibble), or a lazy data frame (e.g., from dbplyr or dtplyr).

.nest_data

A list-column containing data frames

y

A data frame, data frame extension (e.g., a tibble), or a lazy data frame (e.g., from dbplyr or dtplyr).

by

A character vector of variables to join by or a join specification created with join_by().

If NULL, the default, ⁠nest_*_join()⁠ will perform a natural join, using all variables in common across each object in .nest_data and y. A message lists the variables so you can check they're correct; suppress the message by supplying by explicitly.

To join on different variables between the objects in .nest_data and y, use a named vector. For example, by = c("a" = "b") will match .nest_data$a to y$b for each object in .nest_data.

To join by multiple variables, use a vector with length >1. For example, by = c("a", "b") will match .nest_data$a to y$a and .nest_data$b to y$b for each object in .nest_data. Use a named vector to match different variables in .nest_data and y. For example, by = c("a" = "b", "c" = "d") will match .nest_data$a to y$b and .nest_data$c to y$d for each object in .nest_data.

To perform a cross-join, generating all combinations of each object in .nest_data and y, use by = character().

copy

If .nest_data and y are not from the same data source and copy = TRUE then y will be copied into the same src as .nest_data. (Need to review this parameter in more detail for applicability with nplyr)

keep

Should the join keys from both .nest_data and y be preserved in the output?

name

The name of the list column nesting joins create. If NULL, the name of y is used.

...

One or more unquoted expressions separated by commas. Variable names can be used if they were positions in the data frame, so expressions like x:y can be used to select a range of variables.

Details

nest_nest_join() is largely a wrapper around dplyr::nest_join() and maintains the functionality of nest_join() within east nested data frame. For more information on nest_join(), please refer to the documentation in dplyr.

Value

An object of the same type as .data. Each object in the column .nest_data will also be of the same type as the input.

See Also

Other joins: nest-filter-joins, nest-mutate-joins

Examples

gm_nest <- gapminder::gapminder %>% tidyr::nest(country_data = -continent)
gm_codes <- gapminder::country_codes

gm_nest %>% nest_nest_join(country_data, gm_codes, by = "country")