This collection of functions accesses data about grouped SpatVector objects
in various ways:
group_data()returns a tibble that defines the grouping structure. The columns give the values of the grouping variables. The last column, always called.rows, is a list of integer vectors that gives the location of the rows in each group.group_keys()returns a tibble describing the groups.group_rows()returns a list of integer vectors giving the rows that each group contains.group_indices()returns an integer vector the same length as.datathat gives the group that each row belongs to.group_vars()gives names of grouping variables as character vector.groups()gives the names of the grouping variables as a list of symbols.group_size()gives the size of each group.n_groups()gives the total number of groups.
See dplyr::group_data().
Usage
# S3 method for SpatVector
group_data(.data)
# S3 method for SpatVector
group_keys(.tbl, ...)
# S3 method for SpatVector
group_indices(.data, ...)
# S3 method for SpatVector
group_vars(x)
# S3 method for SpatVector
groups(x)
# S3 method for SpatVector
group_size(x)
# S3 method for SpatVector
n_groups(x)Arguments
- .data, .tbl, x
A
SpatVector.- ...
Use of
...is now deprecated; please usegroup_by()first instead.
Value
See the description of the function. The results are usually tibbles,
lists or vectors. These functions does not return SpatVector objects.
Examples
library(terra)
v <- vect(system.file("extdata/cyl.gpkg", package = "tidyterra"))
v$gr_1 <- rep_len(c("A", "A", "B"), length.out = nrow(v))
v$gr_2 <- rep_len(c("C", "D"), length.out = nrow(v))
# Ungrouped
n_groups(v)
#> [1] 1
group_vars(v)
#> character(0)
group_keys(v)
#> # A tibble: 1 × 0
group_size(v)
#> [1] 9
groups(v)
#> list()
group_rows(v)
#> <list_of<integer>[1]>
#> [[1]]
#> [1] 1 2 3 4 5 6 7 8 9
#>
group_data(v)
#> # A tibble: 1 × 1
#> .rows
#> <list<int>>
#> 1 [9]
group_indices(v)
#> [1] 1 1 1 1 1 1 1 1 1
# Grouped by one var
gv <- group_by(v, gr_1)
n_groups(gv)
#> [1] 2
group_vars(gv)
#> [1] "gr_1"
group_keys(gv)
#> # A tibble: 2 × 1
#> gr_1
#> <chr>
#> 1 A
#> 2 B
group_size(gv)
#> [1] 6 3
groups(gv)
#> [[1]]
#> gr_1
#>
group_rows(gv)
#> <list_of<integer>[2]>
#> [[1]]
#> [1] 1 2 4 5 7 8
#>
#> [[2]]
#> [1] 3 6 9
#>
group_data(gv)
#> # A tibble: 2 × 2
#> gr_1 .rows
#> <chr> <list<int>>
#> 1 A [6]
#> 2 B [3]
group_indices(gv)
#> [1] 1 1 2 1 1 2 1 1 2
# Grouped by several vars
gv2 <- group_by(v, gr_1, gr_2)
n_groups(gv2)
#> [1] 4
group_vars(gv2)
#> [1] "gr_1" "gr_2"
group_keys(gv2)
#> # A tibble: 4 × 2
#> gr_1 gr_2
#> <chr> <chr>
#> 1 A C
#> 2 A D
#> 3 B C
#> 4 B D
group_size(gv2)
#> [1] 3 3 2 1
groups(gv2)
#> [[1]]
#> gr_1
#>
#> [[2]]
#> gr_2
#>
group_rows(gv2)
#> <list_of<integer>[4]>
#> [[1]]
#> [1] 1 5 7
#>
#> [[2]]
#> [1] 2 4 8
#>
#> [[3]]
#> [1] 3 9
#>
#> [[4]]
#> [1] 6
#>
group_data(gv2)
#> # A tibble: 4 × 3
#> gr_1 gr_2 .rows
#> <chr> <chr> <list<int>>
#> 1 A C [3]
#> 2 A D [3]
#> 3 B C [2]
#> 4 B D [1]
group_indices(gv2)
#> [1] 1 2 3 2 1 4 1 2 3