geojson_sf: Convert objects to an sf class

In geojsonio: Convert Data from and to 'GeoJSON' or 'TopoJSON'

Description

Convert objects to an sf class

Usage

geojson_sf(x, stringsAsFactors = FALSE, ...)

Arguments

x	Object of class geo_list, geo_json, string, or json
stringsAsFactors	Convert strings to Factors? Default FALSE.
...	Further args passed on to sf::st_read()

Details

The type of sf object returned will depend on the input GeoJSON. Sometimes you will get back a POINTS class, and sometimes a POLYGON class, etc., depending on what the structure of the GeoJSON.

The reading and writing of the CRS to/from geojson is inconsistent. You can directly set the CRS by passing a valid PROJ4 string or epsg code to the crs argument in sf::st_read()

Value

An sf class object, see Details.

Examples

## Not run: 
library(sf)

# geo_list ------------------
## From a numeric vector of length 2 to a point
vec <- c(-99.74,32.45)
geojson_list(vec) %>% geojson_sf

## Lists
## From a list
mylist <- list(list(latitude=30, longitude=120, marker="red"),
               list(latitude=30, longitude=130, marker="blue"))
geojson_list(mylist) %>% geojson_sf
geojson_list(mylist) %>% geojson_sf %>% plot

## From a list of numeric vectors to a polygon
vecs <- list(c(100.0,0.0), c(101.0,0.0), c(101.0,1.0), c(100.0,1.0), c(100.0,0.0))
geojson_list(vecs, geometry="polygon") %>% geojson_sf
geojson_list(vecs, geometry="polygon") %>% geojson_sf %>% plot

# geo_json ------------------
## from point
geojson_json(c(-99.74,32.45)) %>% geojson_sf
geojson_json(c(-99.74,32.45)) %>% geojson_sf %>% plot

# from featurecollectino of points
geojson_json(us_cities[1:2,], lat='lat', lon='long') %>% geojson_sf
geojson_json(us_cities[1:2,], lat='lat', lon='long') %>% geojson_sf %>% plot

# Set the CRS via the crs argument
geojson_json(us_cities[1:2,], lat='lat', lon='long') %>% geojson_sf(crs = "+init=epsg:4326")

# json ----------------------
x <- geojson_json(us_cities[1:2,], lat='lat', lon='long')
geojson_sf(x)

# character string ----------------------
x <- unclass(geojson_json(c(-99.74,32.45)))
geojson_sf(x)

## End(Not run)

geojsonio documentation built on Jan. 15, 2021, 3:33 p.m.