Hierarchical H3 Grid Functions — get

Functions used to traverse the hierarchy of H3 grids.

Usage

get_parents(x, resolution)

get_children(x, resolution)

get_children_count(x, resolution)

get_children_center(x, resolution)

get_children_position(x, resolution)

get_children_at(x, position, resolution)

Arguments

x: an H3 vector.
resolution: a scalar integer representing the grid resolution in the range [0, 15].
position: the integer position in the ordered set of cells.

Value

See details.

Details

get_parents(): returns the parent cells for an H3 vector at a given resolution. Errors if the resolution is smaller than the provided cell.
get_children(): returns a list of H3 vectors containing the children of each H3 cell at a specified resolution. If the resolution is greater than the cell's resolution an empty vector is returned.
get_children_count(): returns an integer vector containing the number of children for each cell at the specified resolution.
get_children_center(): returns the middle child (center child) for all children of an H3 cell at a specified resolution as an H3 vector.
get_children_position(): returns the position of the observed H3 cell in an ordered list of all children as a child of a higher resolution cell (PR for clearer language welcome).
get_children_at(): returns the child of each H3 cell at a specified resolution based on its position in an ordered list (PR for clearer language welcome).

Examples

h3_strs <- c("841f91dffffffff", "841fb59ffffffff")
h3 <- h3_from_strings(h3_strs)

get_parents(h3, 3)
#> <H3[2]>
#> [1] 831f91fffffffff 831fb5fffffffff
get_children(h3, 5)
#> [[1]]
#> <H3[7]>
#> [1] 851f91c3fffffff 851f91c7fffffff 851f91cbfffffff 851f91cffffffff
#> [5] 851f91d3fffffff 851f91d7fffffff 851f91dbfffffff
#> 
#> [[2]]
#> <H3[7]>
#> [1] 851fb583fffffff 851fb587fffffff 851fb58bfffffff 851fb58ffffffff
#> [5] 851fb593fffffff 851fb597fffffff 851fb59bfffffff
#> 
get_children_count(h3, 6)
#> [1] 49 49
get_children_position(h3, 3)
#> [1] 6 4
get_children_at(h3, 999, 10)
#> <H3[2]>
#> [1] 8a1f91c02caffff 8a1fb5802caffff