geojsonio

Convert various data formats to geoJSON or topoJSON

This package is a utility to convert geographic data to geojson and topojson formats. Nothing else. We hope to do this one job very well, and handle all reasonable use cases.

Functions in this package are organized first around what you're working with or want to get, geojson or topojson, then convert to or read from various formats:

geojson_list()/topojson_list() - convert to geojson/topojson as R list format
geojson_json()/topojson_json() - convert to geojson/topojson as json
geojson_read()``topojson_read() - read a geojson/topojson file from file path or URL
geojson_write()/topojson_write() - write a geojson/topojson file locally

Each of the above functions have methods for various objects/classes, including numeric, data.frame, list, SpatialPolygons, SpatialLines, SpatialPoints, etc.

Additional functions:

map_gist() - push up a geojson or topojson file as a GitHub gist (renders as an interactive map)

*json Info

GeoJSON - spec
GeoJSON lint
TopoJSON - spec
TopoJSON node library - on NMP, source

Quick start

Install

Install rgdal - in case you can't get it installed from binary , here's what works on a Mac.

install.packages("http://cran.r-project.org/src/contrib/rgdal_0.9-1.tar.gz", repos = NULL, type="source", configure.args = "--with-gdal-config=/Library/Frameworks/GDAL.framework/Versions/1.10/unix/bin/gdal-config --with-proj-include=/Library/Frameworks/PROJ.framework/unix/include --with-proj-lib=/Library/Frameworks/PROJ.framework/unix/lib")

Install geojsonio

install.packages("devtools")
devtools::install_github("ropensci/geojsonio")

library("geojsonio")

GeoJSON

Convert various formats to geojson

From a numeric vector of length 2, as json or list

geojson_json(c(32.45,-99.74))
#> {"type":"Point","geometry":{"type":"Point","coordinates":[32.45,-99.74]},"properties":{}}
geojson_list(c(32.45,-99.74))
#> $type
#> [1] "Point"
#> 
#> $geometry
#> $geometry$type
#> [1] "Point"
#> 
#> $geometry$coordinates
#> [1]  32.45 -99.74
#> 
#> 
#> $properties
#> NULL
#> 
#> attr(,"class")
#> [1] "geo_list"
#> attr(,"from")
#> [1] "numeric"

From a data.frame

library('maps')
data(us.cities)
geojson_json(us.cities[1:2,], lat='lat', lon='long')
#> {"type":"FeatureCollection","features":[{"type":"Feature","geometry":{"type":"Point","coordinates":[-99.74,32.45]},"properties":{"name":"Abilene TX","country.etc":"TX","pop":"113888","capital":"0"}},{"type":"Feature","geometry":{"type":"Point","coordinates":[-81.52,41.08]},"properties":{"name":"Akron OH","country.etc":"OH","pop":"206634","capital":"0"}}]}
geojson_list(us.cities[1:2,], lat='lat', lon='long')
#> $type
#> [1] "FeatureCollection"
#> 
#> $features
#> $features[[1]]
#> $features[[1]]$type
#> [1] "Feature"
#> 
#> $features[[1]]$geometry
#> $features[[1]]$geometry$type
#> [1] "Point"
#> 
#> $features[[1]]$geometry$coordinates
#> [1] -99.74  32.45
#> 
#> 
#> $features[[1]]$properties
#> $features[[1]]$properties$name
#> [1] "Abilene TX"
#> 
#> $features[[1]]$properties$country.etc
#> [1] "TX"
#> 
#> $features[[1]]$properties$pop
#> [1] "113888"
#> 
#> $features[[1]]$properties$capital
#> [1] "0"
#> 
#> 
#> 
#> $features[[2]]
#> $features[[2]]$type
#> [1] "Feature"
#> 
#> $features[[2]]$geometry
#> $features[[2]]$geometry$type
#> [1] "Point"
#> 
#> $features[[2]]$geometry$coordinates
#> [1] -81.52  41.08
#> 
#> 
#> $features[[2]]$properties
#> $features[[2]]$properties$name
#> [1] "Akron OH"
#> 
#> $features[[2]]$properties$country.etc
#> [1] "OH"
#> 
#> $features[[2]]$properties$pop
#> [1] "206634"
#> 
#> $features[[2]]$properties$capital
#> [1] "0"
#> 
#> 
#> 
#> 
#> attr(,"class")
#> [1] "geo_list"
#> attr(,"from")
#> [1] "data.frame"

From SpatialPolygons class

library('sp')
poly1 <- Polygons(list(Polygon(cbind(c(-100,-90,-85,-100),
  c(40,50,45,40)))), "1")
poly2 <- Polygons(list(Polygon(cbind(c(-90,-80,-75,-90),
  c(30,40,35,30)))), "2")
sp_poly <- SpatialPolygons(list(poly1, poly2), 1:2)

to json

geojson_json(sp_poly)
#> {"type":"FeatureCollection","features":[{"type":"Feature","id":1,"properties":{"dummy":0},"geometry":{"type":"Polygon","coordinates":[[[-100,40],[-90,50],[-85,45],[-100,40]]]}},{"type":"Feature","id":2,"properties":{"dummy":0},"geometry":{"type":"Polygon","coordinates":[[[-90,30],[-80,40],[-75,35],[-90,30]]]}}]}

to list

geojson_list(sp_poly)$coordinates[[1]]
#> NULL

Write geojson

library('maps')
data(us.cities)
geojson_write(us.cities[1:2,], lat='lat', lon='long')
#> [1] "myfile.geojson"

Read geojson

file <- system.file("examples", "california.geojson", package = "geojsonio")
out <- geojson_read(file)
#> OGR data source with driver: GeoJSON 
#> Source: "/Users/sacmac/Library/R/3.1/library/geojsonio/examples/california.geojson", layer: "OGRGeoJSON"
#> with 1 features and 11 fields
#> Feature type: wkbMultiPolygon with 2 dimensions
plot(out)

TopoJSON

Convert to TopoJSON with Node topojson client

For topojson you will need Mike Bostock's command line client. Install it by doing

sudo npm install -g topojson

Download a zipped shape fileset, this one for distribution of Quercus wislizeni. Unzip the zip file to a folder. Then do (changing the path to your path)

topojson_write(shppath='~/Downloads/querwisl', path = "~/Downloads", projection='albers', projargs=list(rotate='[60, -35, 0]'))
#> Error in ogrListLayers(fullpathtoshp): Cannot open data source

Which prints progress on the conversion of the shape file. And prints the topojson CLI call, including the location of the output file, here /Users/sacmac/querwisl.json

OGR data source with driver: ESRI Shapefile
Source: "/Users/sacmac/Downloads/querwisl", layer: "querwisl"
with 35 features and 5 fields
Feature type: wkbPolygon with 2 dimensions
topojson -o /Users/sacmac/querwisl.json -q 1e4 -s 0 --shapefile-encoding utf8 --projection 'd3.geo.albers().rotate([60, -35, 0])' -- /var/folders/gs/4khph0xs0436gmd2gdnwsg080000gn/T//Rtmp49APW7/querwisl.shp

bounds: -403.2554825867553 401.27189387582916 -295.798050380061 585.4214768677039 (cartesian)
pre-quantization: 0.010746817902459677 0.018416799979185387
topology: 35 arcs, 2492 points
prune: retained 35 / 35 arcs (100%)

You can then use this topojson file wherever. We'll add a function soon to automagically throw this file up as a Github gist to get an interactive map.

Read topojson

TopoJSON

url <- "https://raw.githubusercontent.com/shawnbot/d3-cartogram/master/data/us-states.topojson"
out <- topojson_read(url)
#> OGR data source with driver: GeoJSON 
#> Source: "https://raw.githubusercontent.com/shawnbot/d3-cartogram/master/data/us-states.topojson", layer: "states"
#> with 51 features and 2 fields
#> Feature type: wkbPolygon with 2 dimensions
plot(out)

Use case: Play with US states

Using data from https://github.com/glynnbird/usstatesgeojson

Get some geojson

library('httr')
res <- GET('https://api.github.com/repos/glynnbird/usstatesgeojson/contents')
st_names <- Filter(function(x) grepl("\\.geojson", x), sapply(content(res), "[[", "name"))
base <- 'https://raw.githubusercontent.com/glynnbird/usstatesgeojson/master/'
st_files <- paste0(base, st_names)

Make a faceted plot

library('ggplot2')
library('plyr')
st_use <- st_files[7:13]
geo <- lapply(st_use, geojson_read, verbose = FALSE)
df <- ldply(setNames(lapply(geo, fortify), gsub("\\.geojson", "", st_names[7:13])))
ggplot(df, aes(long, lat, group = group)) +
  geom_polygon() +
  facet_wrap(~ .id, scales = "free")

craigcitro / geojsonio Goto Github PK

geojsonio's Introduction

geojsonio

*json Info

Quick start

Install

GeoJSON

Convert various formats to geojson

Write geojson

Read geojson

TopoJSON

Convert to TopoJSON with Node topojson client

Read topojson

Use case: Play with US states

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