h3jsr provides access to Uber’s H3 library
via its javascript transpile, using the
magical power of V8
.
H3 is a hexagonal hierarchical geospatial indexing system. Details about its structure and use cases can be found here.
Install from github with
devtools::install_github("obrl-soil/h3jsr")
library(h3jsr)
library(sf)
#> Linking to GEOS 3.6.1, GDAL 2.2.3, PROJ 4.9.3
# where is the Brisbane Town Hall at resolution 15?
bth <- st_sfc(st_point(c(153.023503, -27.468920)), crs = 4326)
point_to_h3(bth, res = 15)
#> [1] "8fbe8d12acad2f3"
# where is it at several resolutions?
point_to_h3(bth, res = seq(10, 15), simple = FALSE)
#> h3_resolution_10 h3_resolution_11 h3_resolution_12 h3_resolution_13
#> 1 8abe8d12acaffff 8bbe8d12acadfff 8cbe8d12acad3ff 8dbe8d12acad2ff
#> h3_resolution_14 h3_resolution_15
#> 1 8ebe8d12acad2f7 8fbe8d12acad2f3
# Where is the center of the hexagon over the Brisbane Town
# Hall at resolution 10?
brisbane_10 <- h3_to_point(h3_address = '8abe8d12acaffff')
brisbane_10
#> Geometry set for 1 feature
#> geometry type: POINT
#> dimension: XY
#> bbox: xmin: 153.0239 ymin: -27.46853 xmax: 153.0239 ymax: -27.46853
#> epsg (SRID): 4326
#> proj4string: +proj=longlat +datum=WGS84 +no_defs
#> POINT (153.0239 -27.46853)
# Is that a valid H3 address?
is_valid(h3_address = '8abe8d12acaffff')
#> [1] TRUE
# is it a pentagon?
is_pentagon(h3_address = '8abe8d12acaffff')
#> [1] FALSE
# is it Class III?
is_rc3(h3_address = '8abe8d12acaffff')
#> [1] FALSE
# What is Brisbane Town Hall's base cell number?
get_base_cell(h3_address = '8abe8d12acaffff')
#> [1] 95
# What is the hexagon over the Brisbane Town Hall at resolution 10?
brisbane_hex_10 <- h3_to_polygon(input = '8abe8d12acaffff', simple = FALSE)
# if you're feeling fancy,
# point_to_h3(bth, res = seq(10,15)) %>%
# unlist() %>%
# h3_to_polygon(., simple = FALSE) %>%
# mapview::mapview()
Props to Joel Gombin, who’s package
concaveman
provided me
with the implementation inspo.