Nest join SpatVector objects — nest_join.SpatVector • tidyterra

nest_join() returns a tibble with the attributes and geometry of x, plus a list-column containing matching rows from y.

Usage

# S3 method for class 'SpatVector'
nest_join(
  x,
  y,
  by = NULL,
  copy = FALSE,
  keep = NULL,
  name = NULL,
  ...,
  na_matches = c("na", "never")
)

Arguments

x

A SpatVector.

y

A data frame. Spatial y inputs are not supported; use spatial joins from terra for that workflow.

by

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

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

To join on different variables between x and y, use a join_by() specification. For example, join_by(a == b) will match x$a to y$b.

To join by multiple variables, use a join_by() specification with multiple expressions. For example, join_by(a == b, c == d) will match x$a to y$b and x$c to y$d. If the column names are the same between x and y, you can shorten this by listing only the variable names, like join_by(a, c).

join_by() can also be used to perform inequality, rolling, and overlap joins. See the documentation at ?join_by for details on these types of joins.

For simple equality joins, you can alternatively specify a character vector of variable names to join by. For example, by = c("a", "b") joins x$a to y$a and x$b to y$b. If variable names differ between x and y, use a named character vector like by = c("x_a" = "y_a", "x_b" = "y_b").

To perform a cross-join, generating all combinations of x and y, see cross_join().

copy

If x and y are not from the same data source, and copy is TRUE, then y will be copied into the same src as x. This allows you to join tables across srcs, but it is a potentially expensive operation so you must opt into it.

keep

Should the new list-column contain join keys? The default will preserve the join keys for inequality joins.

name

The name of the list-column created by the join. If NULL, the default, the name of y is used.

...

Other parameters passed onto methods.

na_matches

Should two NA or two NaN values match?

"na", the default, treats two NA or two NaN values as equal, like %in%, match(), and merge().
"never" treats two NA or two NaN values as different, and will never match them together or to any other values. This is similar to joins for database sources and to base::merge(incomparables = NA).

Value

A tibble.

Methods

Implementation of the generic dplyr::nest_join() method.

`SpatVector`

The output is a tibble with the attributes and WKT geometry of x, plus a list-column with matching rows from y.

Examples

v <- terra::vect(system.file("extdata/cyl.gpkg", package = "tidyterra"))
extra <- tibble::tibble(cpro = c("05", "09"), value = c(1, 2))

nest_join(v, extra, by = "cpro")
#> # A tibble: 9 × 5
#>   iso2  cpro  name       geometry                                          data 
#> * <chr> <chr> <chr>      <chr>                                             <lis>
#> 1 ES-AV 05    Avila      POLYGON ((3126360.241699999 2066777.7545, 312507… <df> 
#> 2 ES-BU 09    Burgos     MULTIPOLYGON (((3276730.9088 2262326.4267999995,… <df> 
#> 3 ES-LE 24    Leon       POLYGON ((3049427.446799999 2233672.9251, 304906… <df> 
#> 4 ES-P  34    Palencia   MULTIPOLYGON (((3175411.4093999993 2291867.77349… <df> 
#> 5 ES-SA 37    Salamanca  POLYGON ((3042660.9637 2138939.4168, 3043433.893… <df> 
#> 6 ES-SG 40    Segovia    POLYGON ((3126360.241699999 2066777.7545, 312403… <df> 
#> 7 ES-SO 42    Soria      POLYGON ((3194084.32 2154250.846, 3194361.6882 2… <df> 
#> 8 ES-VA 47    Valladolid MULTIPOLYGON (((3158119.9080999997 2161552.0975,… <df> 
#> 9 ES-ZA 49    Zamora     POLYGON ((3042660.9637 2138939.4168, 3040850.710… <df>

Nest join `SpatVector` objects