file_to_geojson: Convert spatial data files to GeoJSON from various formats.

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

Convert spatial data files to GeoJSON from various formats.

Description

You can use a web interface called Ogre, or do conversions locally using the sf package.

Usage

file_to_geojson(
  input,
  method = "web",
  output = ".",
  parse = FALSE,
  encoding = "CP1250",
  verbose = FALSE,
  ...
)

Arguments

input	The file being uploaded, path to the file on your machine.
method	(character) One of "web" (default) or "local". Matches on partial strings. This parameter determines how the data is read. "web" means we use the Ogre web service, and "local" means we use sf. See Details fore more.
output	Destination for output geojson file. Defaults to current working directory, and gives a random alphanumeric file name
parse	(logical) To parse geojson to data.frame like structures if possible. Default: FALSE
encoding	(character) The encoding passed to sf::st_read(). Default: CP1250
verbose	(logical) Printing of sf::st_read() progress. Default: FALSE
...	Additional parameters passed to st_read

Value

path for the geojson file

Method parameter

The web option uses the Ogre web API. Ogre currently has an output size limit of 15MB. See here http://ogre.adc4gis.com/ for info on the Ogre web API. The local option uses the function st_write from the package rgdal.

Ogre

Note that for Shapefiles, GML, MapInfo, and VRT, you need to send zip files to Ogre. For other file types (.bna, .csv, .dgn, .dxf, .gxt, .txt, .json, .geojson, .rss, .georss, .xml, .gmt, .kml, .kmz) you send the actual file with that file extension.

Linting GeoJSON

If you're having trouble rendering GeoJSON files, ensure you have a valid GeoJSON file by running it through the package geojsonlint, which has a variety of different GeoJSON linters.

File size

When using method="web", be aware of file sizes. https://ogre.adc4gis.com that we use for this option does not document what file size is too large, but you should get an error message like "maximum file length exceeded" when that happens. method="local" shouldn't be sensitive to file sizes.

Examples

## Not run: 
file <- system.file("examples", "norway_maple.kml", package = "geojsonio")

# KML type file - using the web method
file_to_geojson(input = file, method = "web", output = "kml_web")
## read into memory
file_to_geojson(input = file, method = "web", output = ":memory:")
file_to_geojson(input = file, method = "local", output = ":memory:")

# KML type file - using the local method
file_to_geojson(input = file, method = "local", output = "kml_local")

# Shp type file - using the web method - input is a zipped shp bundle
file <- system.file("examples", "bison.zip", package = "geojsonio")
file_to_geojson(file, method = "web", output = "shp_web")

# Shp type file - using the local method - input is the actual .shp file
file <- system.file("examples", "bison.zip", package = "geojsonio")
dir <- tempdir()
unzip(file, exdir = dir)
list.files(dir)
shpfile <- file.path(dir, "bison-Bison_bison-20130704-120856.shp")
file_to_geojson(shpfile, method = "local", output = "shp_local")

# geojson with .json extension
## this doesn't work anymore, hmmm
# x <- gsub("\n", "", paste0('https://gist.githubusercontent.com/hunterowens/
# 25ea24e198c80c9fbcc7/raw/7fd3efda9009f902b5a991a506cea52db19ba143/
# wards2014.json', collapse = ""))
# res <- file_to_geojson(x)
# jsonlite::fromJSON(res)
# res <- file_to_geojson(x, method = "local")
# jsonlite::fromJSON(res)

## End(Not run)

geojsonio documentation built on Sept. 8, 2023, 5:54 p.m.