wellknown - convert WKT to GeoJSON and vice versa.
Inspiration partly comes from Python’s geomet/geomet - and the name from Javascript’s wellknown (it’s a good name).
Different interfaces
WKT from R stuctures
There’s a family of functions that make it easy to go from familiar R objects like lists and data.frames to WKT, including:
-
point()- make a point, e.g.,POINT (-116 45) -
multipoint()- make a multipoint, e.g.,MULTIPOINT ((100 3), (101 2)) -
linestring()- make a linestring, e.g.,LINESTRING (100 0, 101 1) -
polygon()- make a polygon, e.g.,POLYGON ((100 0), (101 0), (101 1), (100 0)) -
multipolygon()- make a multipolygon, e.g.,MULTIPOLYGON (((30 20, 45 40, 10 40, 30 20)), ((15 5, 40 10, 10 20, 5 10, 15 5)))
The above currently accept (depending on the fxn) numeric, list, and data.frame (and character for special case of EMPTY WKT objects).
Geojson to WKT and vice versa
geojson2wkt() and wkt2geojson() cover a subset of the various formats available:
PointMultiPointPolygonMultiPolygonLineStringMultilineStringGeometrycollection
Geojson to WKT
geojson2wkt() converts any geojson as a list to a WKT string (the same format )
WKT to Geojson
wkt2geojson() converts any WKT string into geojson as a list. This list format for geojson can be used downstream e.g., in the leaflet package.
Install
Stable version
install.packages("wellknown")
Dev version
remotes::install_github("ropensci/wellknown")
GeoJSON to WKT
Point
point <- list(Point = c(116.4, 45.2, 11.1)) geojson2wkt(point) #> [1] "POINT Z(116.4000000000000057 45.2000000000000028 11.0999999999999996)"
Multipoint
mp <- list( MultiPoint = matrix(c(100, 101, 3.14, 3.101, 2.1, 2.18), ncol = 2) ) geojson2wkt(mp) #> [1] "MULTIPOINT ((100.0000000000000000 3.1010000000000000), (101.0000000000000000 2.1000000000000001), (3.1400000000000001 2.1800000000000002))"
LineString
st <- list( LineString = matrix(c(0.0, 2.0, 4.0, 5.0, 0.0, 1.0, 2.0, 4.0), ncol = 2) ) geojson2wkt(st, fmt=0) #> [1] "LINESTRING (0 0, 2 1, 4 2, 5 4)"
Multilinestring
multist <- list( MultiLineString = list( matrix(c(0, -2, -4, -1, -3, -5), ncol = 2), matrix(c(1.66, 10.9999, 10.9, 0, -31.5, 3.0, 1.1, 0), ncol = 2) ) ) geojson2wkt(multist) #> [1] "MULTILINESTRING ((0.0000000000000000 -1.0000000000000000, -2.0000000000000000 -3.0000000000000000, -4.0000000000000000 -5.0000000000000000), (1.6599999999999999 -31.5000000000000000, 10.9999000000000002 3.0000000000000000, 10.9000000000000004 1.1000000000000001, 0.0000000000000000 0.0000000000000000))"
Polygon
poly <- list( Polygon = list( matrix(c(100.001, 101.1, 101.001, 100.001, 0.001, 0.001, 1.001, 0.001), ncol = 2), matrix(c(100.201, 100.801, 100.801, 100.201, 0.201, 0.201, 0.801, 0.201), ncol = 2) ) ) geojson2wkt(poly) #> [1] "POLYGON ((100.0010000000000048 0.0010000000000000, 101.0999999999999943 0.0010000000000000, 101.0010000000000048 1.0009999999999999, 100.0010000000000048 0.0010000000000000), (100.2009999999999934 0.2010000000000000, 100.8010000000000019 0.2010000000000000, 100.8010000000000019 0.8010000000000000, 100.2009999999999934 0.2010000000000000))"
Multipolygon
mpoly <- list( MultiPolygon = list( list( matrix(c(100, 101, 101, 100, 0.001, 0.001, 1.001, 0.001), ncol = 2), matrix(c(100.2, 100.8, 100.8, 100.2, 0.2, 0.2, 0.8, 0.2), ncol = 2) ), list( matrix(c(1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 1.0), ncol = 3), matrix(c(9.0, 10.0, 11.0, 12.0, 1.0, 2.0, 3.0, 4.0, 9.0), ncol = 3) ) ) ) geojson2wkt(mpoly, fmt=1) #> [1] "MULTIPOLYGON Z(((100.000 0.001 0.000, 101.000 0.001 0.000, 101.000 1.001 0.000, 100.000 0.001 0.000), (100.2 0.2 0.0, 100.8 0.2 0.0, 100.8 0.8 0.0, 100.2 0.2 0.0)), ((1.0 4.0 7.0, 2.0 5.0 8.0, 3.0 6.0 1.0), (9.0 12.0 3.0, 10.0 1.0 4.0, 11.0 2.0 9.0)))"
GeometryCollection
gmcoll <- list( GeometryCollection = list( list(type = 'Point', coordinates = c(0.0, 1.0)), list(type = 'LineString', coordinates = matrix(c(0.0, 2.0, 4.0, 5.0, 0.0, 1.0, 2.0, 4.0), ncol = 2)), list(type = 'Polygon', coordinates = list( matrix(c(100.001, 101.1, 101.001, 100.001, 0.001, 0.001, 1.001, 0.001), ncol = 2), matrix(c(100.201, 100.801, 100.801, 100.201, 0.201, 0.201, 0.801, 0.201), ncol = 2) )) ) ) geojson2wkt(gmcoll, fmt=0) #> [1] "GEOMETRYCOLLECTION (POINT (0 1), LINESTRING (0 0, 2 1, 4 2, 5 4), POLYGON ((100.001 0.001, 101.100 0.001, 101.001 1.001, 100.001 0.001), (100.201 0.201, 100.801 0.201, 100.801 0.801, 100.201 0.201)))"
Convert json or character objects
You can convert directly from an object of class json, which is output from jsonlite::toJSON().
library("jsonlite") (json <- toJSON(list(Point = c(-105, 39)), auto_unbox = TRUE)) #> {"Point":[-105,39]}
geojson2wkt(json) #> [1] "POINT (-105 39)"
And you can convert from a geojson character string:
str <- '{"type":"LineString","coordinates":[[0,0,10],[2,1,20],[4,2,30],[5,4,40]]}' geojson2wkt(str) #> [1] "LINESTRING Z(0 0 10, 2 1 20, 4 2 30, 5 4 40)"
WKT to GeoJSON
Point
As a Feature
str <- "POINT (-116.4000000000000057 45.2000000000000028)" wkt2geojson(str) #> $type #> [1] "Feature" #> #> $geometry #> $geometry$type #> [1] "Point" #> #> $geometry$coordinates #> [1] -116.4 45.2 #> ...
Not Feature
wkt2geojson(str, feature=FALSE) #> $type #> [1] "Point" #> #> $coordinates #> [1] -116.4 45.2 #> #> attr(,"class") #> [1] "geojson"
Multipoint
str <- 'MULTIPOINT ((100.000 3.101), (101.000 2.100), (3.140 2.180))' wkt2geojson(str, feature=FALSE) #> $type #> [1] "MultiPoint" #> #> $coordinates #> [,1] [,2] #> [1,] 100.00 3.101 #> [2,] 101.00 2.100 #> [3,] 3.14 2.180 #> #> attr(,"class") ...
Polygon
str <- "POLYGON ((100 0.1, 101.1 0.3, 101 0.5, 100 0.1), (103.2 0.2, 104.8 0.2, 100.8 0.8, 103.2 0.2))" wkt2geojson(str, feature=FALSE) #> $type #> [1] "Polygon" #> #> $coordinates #> $coordinates[[1]] #> [,1] [,2] #> [1,] 100.0 0.1 #> [2,] 101.1 0.3 #> [3,] 101.0 0.5 #> [4,] 100.0 0.1 ...
MultiPolygon
str <- "MULTIPOLYGON (((40 40, 20 45, 45 30, 40 40)), ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20)))" wkt2geojson(str, feature=FALSE) #> $type #> [1] "MultiPolygon" #> #> $coordinates #> $coordinates[[1]] #> $coordinates[[1]][[1]] #> [,1] [,2] #> [1,] 40 40 #> [2,] 20 45 #> [3,] 45 30 ...
Linestring
wkt2geojson("LINESTRING (0 -1, -2 -3, -4 5)", feature=FALSE) #> $type #> [1] "LineString" #> #> $coordinates #> [,1] [,2] #> [1,] 0 -1 #> [2,] -2 -3 #> [3,] -4 5 #> #> attr(,"class") ...
lint WKT
lint("POINT (1 2)") #> [1] TRUE lint("LINESTRING EMPTY") #> [1] TRUE lint("MULTIPOINT ((1 2), (3 4), (-10 100))") #> [1] TRUE lint("POLYGON((20.3 28.6, 20.3 19.6, 8.5 19.6, 8.5 28.6, 20.3 28.6))") #> [1] TRUE lint("MULTIPOLYGON (((30 20, 45 40, 10 40, 30 20)), ((15 5, 40 10, 10 20, 5 10, 15 5)))") #> [1] TRUE lint("POINT (1 2 3 4 5)") #> [1] FALSE lint("LINESTRING (100)") #> [1] FALSE lint("MULTIPOLYGON (((30 20, 45 40, 10 40, 30 20)), ((15 5, a b, 10 20, 5 10, 15 5)))") #> [1] FALSE
WKT <–> WKB
WKT to WKB
## point wkt_wkb("POINT (-116.4 45.2)") #> [1] 01 01 00 00 00 9a 99 99 99 99 19 5d c0 9a 99 99 99 99 99 46 40 ## polygon wkt_wkb("POLYGON ((100.0 0.0, 101.1 0.0, 101.0 1.0, 100.0 0.0))") #> [1] 01 03 00 00 00 01 00 00 00 04 00 00 00 00 00 00 00 00 00 59 40 00 00 00 00 #> [26] 00 00 00 00 66 66 66 66 66 46 59 40 00 00 00 00 00 00 00 00 00 00 00 00 00 #> [51] 40 59 40 00 00 00 00 00 00 f0 3f 00 00 00 00 00 00 59 40 00 00 00 00 00 00 #> [76] 00 00
WKB to WKT
## point (x <- wkt_wkb("POINT (-116.4 45.2)")) #> [1] 01 01 00 00 00 9a 99 99 99 99 19 5d c0 9a 99 99 99 99 99 46 40 wkb_wkt(x) #> [1] "POINT(-116.4 45.2)" ## polygon (x <- wkt_wkb("POLYGON ((100.0 0.0, 101.1 0.0, 101.0 1.0, 100.0 0.0))")) #> [1] 01 03 00 00 00 01 00 00 00 04 00 00 00 00 00 00 00 00 00 59 40 00 00 00 00 #> [26] 00 00 00 00 66 66 66 66 66 46 59 40 00 00 00 00 00 00 00 00 00 00 00 00 00 #> [51] 40 59 40 00 00 00 00 00 00 f0 3f 00 00 00 00 00 00 59 40 00 00 00 00 00 00 #> [76] 00 00 wkb_wkt(x) #> [1] "POLYGON((100 0,101.1 0,101 1,100 0))"
Meta
- Please report any issues or bugs.
- License: MIT
- Get citation information for
wellknownin R doingcitation(package = 'wellknown') - Please note that this project is released with a Contributor Code of Conduct. By participating in this project you agree to abide by its terms.