README

geojson aims to deal only with geojson data, without requiring any of the sp/rgdal/rgeos stack. That means this package is light weight.

We’ve defined classes (S3) following the GeoJSON spec. These classes sort of overlap with sp’s classes, but not really. There’s also some overlap in GeoJSON classes with Well-Known Text (WKT) classes, but GeoJSON has a subset of WKT’s classes.

The package geoops supports manipulations on the classes defined in this package. This package is used within geojsonio to make some tasks easier.

Installation

install.packages("geojson")

devtools::install_github("ropensci/geojson")

library("geojson")

geojson class

Essentially a character string with S3 class geojson attached to make it easy to perform operations on

x <- "{\"type\":\"FeatureCollection\",\"features\":[{\"type\":\"Feature\",\"geometry\":{\"type\":\"Point\",\"coordinates\":[-99.74,32.45]},\"properties\":{}}]}"
as.geojson(x)
#> <geojson> 
#>   type:  FeatureCollection 
#>   bounding box:  -99.74 32.45 -99.74 32.45 
#>   features (n): 1 
#>   features (geometry / length):
#>     Point / 2

geometrycollection

x <- '{
 "type": "GeometryCollection",
 "geometries": [
   {
     "type": "Point",
     "coordinates": [100.0, 0.0]
   },
   {
     "type": "LineString",
     "coordinates": [ [101.0, 0.0], [102.0, 1.0] ]
   }
  ]
}'
(y <- geometrycollection(x))
#> <GeometryCollection> 
#>   geometries (n): 2 
#>   geometries (geometry / length):
#>     Point / 2
#>     LineString / 2

inspect the object

y[[1]]
#> [1] "{\n \"type\": \"GeometryCollection\",\n \"geometries\": [\n   {\n     \"type\": \"Point\",\n     \"coordinates\": [100.0, 0.0]\n   },\n   {\n     \"type\": \"LineString\",\n     \"coordinates\": [ [101.0, 0.0], [102.0, 1.0] ]\n   }\n  ]\n}"

geo_type(y)
#> [1] "GeometryCollection"

geo_pretty(y)
#> {
#>     "type": "GeometryCollection",
#>     "geometries": [
#>         {
#>             "type": "Point",
#>             "coordinates": [
#>                 100.0,
#>                 0.0
#>             ]
#>         },
#>         {
#>             "type": "LineString",
#>             "coordinates": [
#>                 [
#>                     101.0,
#>                     0.0
#>                 ],
#>                 [
#>                     102.0,
#>                     1.0
#>                 ]
#>             ]
#>         }
#>     ]
#> }
#>

geo_write(y, f <- tempfile(fileext = ".geojson"))
jsonlite::fromJSON(f, FALSE)
#> $type
#> [1] "GeometryCollection"
#> 
#> $geometries
#> $geometries[[1]]
#> $geometries[[1]]$type
#> [1] "Point"
#> 
#> $geometries[[1]]$coordinates
#> $geometries[[1]]$coordinates[[1]]
#> [1] 100
#> 
#> $geometries[[1]]$coordinates[[2]]
#> [1] 0
#> 
#> 
#> 
#> $geometries[[2]]
#> $geometries[[2]]$type
#> [1] "LineString"
#> 
#> $geometries[[2]]$coordinates
#> $geometries[[2]]$coordinates[[1]]
#> $geometries[[2]]$coordinates[[1]][[1]]
#> [1] 101
#> 
#> $geometries[[2]]$coordinates[[1]][[2]]
#> [1] 0
#> 
#> 
#> $geometries[[2]]$coordinates[[2]]
#> $geometries[[2]]$coordinates[[2]][[1]]
#> [1] 102
#> 
#> $geometries[[2]]$coordinates[[2]][[2]]
#> [1] 1

properties

x <- '{ "type": "LineString", "coordinates": [ [100.0, 0.0], [101.0, 1.0] ]}'
res <- linestring(x) %>% feature() %>% properties_add(population = 1000)
res
#> <Feature> 
#>   type:  LineString 
#>   coordinates:  [[100,0],[101,1]]

properties_get(res, property = 'population')
#> 1000

crs

crs <- '{
  "type": "name",
  "properties": {
     "name": "urn:ogc:def:crs:OGC:1.3:CRS84"
  }
}'
z <- x %>% feature() %>% crs_add(crs)
z
#> {
#>     "type": "Feature",
#>     "properties": {
#> 
#>     },
#>     "geometry": {
#>         "type": "LineString",
#>         "coordinates": [
#>             [
#>                 100,
#>                 0
#>             ],
#>             [
#>                 101,
#>                 1
#>             ]
#>         ]
#>     },
#>     "crs": {
#>         "type": "name",
#>         "properties": {
#>             "name": "urn:ogc:def:crs:OGC:1.3:CRS84"
#>         }
#>     }
#> }

crs_get(z)
#> $type
#> [1] "name"
#> 
#> $properties
#> $properties$name
#> [1] "urn:ogc:def:crs:OGC:1.3:CRS84"

bbox

tt <- x %>% feature() %>% bbox_add()
tt
#> {
#>     "type": "Feature",
#>     "properties": {
#> 
#>     },
#>     "geometry": {
#>         "type": "LineString",
#>         "coordinates": [
#>             [
#>                 100,
#>                 0
#>             ],
#>             [
#>                 101,
#>                 1
#>             ]
#>         ]
#>     },
#>     "bbox": [
#>         100,
#>         0,
#>         101,
#>         1
#>     ]
#> }

bbox_get(tt)
#> [1] 100   0 101   1

geojson in data.frame’s

x <- '{ "type": "Point", "coordinates": [100.0, 0.0] }'
(pt <- point(x))
#> <Point> 
#>   coordinates:  [100,0]

library("tibble")
tibble(a = 1:5, b = list(pt))
#> # A tibble: 5 x 2
#>       a b             
#>   <int> <list>        
#> 1     1 <S3: geopoint>
#> 2     2 <S3: geopoint>
#> 3     3 <S3: geopoint>
#> 4     4 <S3: geopoint>
#> 5     5 <S3: geopoint>

x <- '{ "type": "MultiLineString",
  "coordinates": [ [ [100.0, 0.0], [101.0, 1.0] ], [ [102.0, 2.0], [103.0, 3.0] ] ] }'
(mls <- multilinestring(x))
#> <MultiLineString> 
#>   no. lines:  2 
#>   no. nodes / line:  2, 2 
#>   coordinates:  [[[100,0],[101,1]],[[102,2],[103,3]]]

tibble(a = 1:5, b = list(mls))
#> # A tibble: 5 x 2
#>       a b                       
#>   <int> <list>                  
#> 1     1 <S3: geomultilinestring>
#> 2     2 <S3: geomultilinestring>
#> 3     3 <S3: geomultilinestring>
#> 4     4 <S3: geomultilinestring>
#> 5     5 <S3: geomultilinestring>

tibble(a = 1:5, b = list(pt), c = list(mls))
#> # A tibble: 5 x 3
#>       a b              c                       
#>   <int> <list>         <list>                  
#> 1     1 <S3: geopoint> <S3: geomultilinestring>
#> 2     2 <S3: geopoint> <S3: geomultilinestring>
#> 3     3 <S3: geopoint> <S3: geomultilinestring>
#> 4     4 <S3: geopoint> <S3: geomultilinestring>
#> 5     5 <S3: geopoint> <S3: geomultilinestring>

geobuf

file <- system.file("examples/test.pb", package = "geojson")
(json <- from_geobuf(file))
#> {"type":"FeatureCollection","features":[{"type":"Feature","geometry":{"type":"Point","coordinates":[102,0.5]},"id":999,"properties":{"prop0":"value0","double":0.0123,"negative_int":-100,"positive_int":100,"negative_double":-1.2345e+16,"positive_double":1.2345e+16,"null":null,"array":[1,2,3.1],"object":{"foo":[5,6,7]}},"blabla":{"foo":[1,1,1]}},{"type":"Feature","geometry":{"type":"LineString","coordinates":[[102,0],[103,-1.1],[104,-3],[105,1]]},"id":123,"properties":{"custom1":"test","prop0":"value0","prop1":0}},{"type":"Feature","geometry":{"type":"Polygon","coordinates":[[[100,0],[101,0],[101,1],[100,1],[100,0]],[[99,10],[101,0],[100,1],[99,10]]]},"id":"test-id","properties":{"prop0":"value0","prop1":{"this":"that"}},"custom1":"jeroen"},{"type":"Feature","geometry":{"type":"MultiPolygon","coordinates":[[[[102,2],[103,2],[103,3],[102,2]]],[[[100,0],[101,0],[101,1],[100,1],[100,0]],[[100.2,0.2],[100.2,0.8],[100.2,0.2]]]]}},{"type":"Feature","geometry":{"type":"GeometryCollection","geometries":[{"type":"Point","coordinates":[100,0]},{"type":"LineString","coordinates":[[101,0],[102,1]]},{"type":"MultiPoint","coordinates":[[100,0],[101,1]]},{"type":"MultiLineString","coordinates":[[[100,0],[101,1]],[[102,2],[103,3]]]},{"type":"MultiPolygon","coordinates":[[[[102,2],[103,2],[103,3],[102,3],[102,2]]],[[[100,0],[101,0],[101,1],[100,1],[100,0]],[[100.2,0.2],[100.8,0.2],[100.8,0.8],[100.2,0.8],[100.2,0.2]]]]}]}}]}
pb <- to_geobuf(json)
class(pb)
#> [1] "raw"
f <- tempfile(fileext = ".pb")
to_geobuf(json, f)
from_geobuf(f)
#> {"type":"FeatureCollection","features":[{"type":"Feature","geometry":{"type":"Point","coordinates":[102,0.5]},"id":999,"properties":{"prop0":"value0","double":0.0123,"negative_int":-100,"positive_int":100,"negative_double":-1.2345e+16,"positive_double":1.2345e+16,"null":null,"array":[1,2,3.1],"object":{"foo":[5,6,7]}},"blabla":{"foo":[1,1,1]}},{"type":"Feature","geometry":{"type":"LineString","coordinates":[[102,0],[103,-1.1],[104,-3],[105,1]]},"id":123,"properties":{"custom1":"test","prop0":"value0","prop1":0}},{"type":"Feature","geometry":{"type":"Polygon","coordinates":[[[100,0],[101,0],[101,1],[100,1],[100,0]],[[99,10],[101,0],[100,1],[99,10]]]},"id":"test-id","properties":{"prop0":"value0","prop1":{"this":"that"}},"custom1":"jeroen"},{"type":"Feature","geometry":{"type":"MultiPolygon","coordinates":[[[[102,2],[103,2],[103,3],[102,2]]],[[[100,0],[101,0],[101,1],[100,1],[100,0]],[[100.2,0.2],[100.2,0.8],[100.2,0.2]]]]}},{"type":"Feature","geometry":{"type":"GeometryCollection","geometries":[{"type":"Point","coordinates":[100,0]},{"type":"LineString","coordinates":[[101,0],[102,1]]},{"type":"MultiPoint","coordinates":[[100,0],[101,1]]},{"type":"MultiLineString","coordinates":[[[100,0],[101,1]],[[102,2],[103,3]]]},{"type":"MultiPolygon","coordinates":[[[[102,2],[103,2],[103,3],[102,3],[102,2]]],[[[100,0],[101,0],[101,1],[100,1],[100,0]],[[100.2,0.2],[100.8,0.2],[100.8,0.8],[100.2,0.8],[100.2,0.2]]]]}]}}]}

x <- '{ "type": "Polygon",
"coordinates": [
  [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0], [100.0, 1.0], [100.0, 0.0] ]
  ]
}'
y <- polygon(x)
to_geobuf(y)
#>  [1] 10 02 18 06 2a 1a 0a 18 08 04 12 01 04 1a 11 80 84 af 5f 00 80 89 7a
#> [24] 00 00 80 89 7a ff 88 7a 00

x <- '{"type": "MultiPoint", "coordinates": [ [100.0, 0.0], [101.0, 1.0] ] }'
y <- multipoint(x)
to_geobuf(y)
#>  [1] 10 02 18 06 2a 11 0a 0f 08 01 1a 0b 80 84 af 5f 00 80 89 7a 80 89 7a

geojson