CODEWITHSUNDEEP
rleafletgeojson
wjy_202
wjy_202

Reputation: 41

I am trying to make an interactive map using leafletR package according to a ZevRoss blog. But there is an error in the code

The ZevRoss blog is as follow: http://zevross.com/blog/2014/04/11/using-r-to-quickly-create-an-interactive-online-map-using-the-leafletr-package/

The code with error is: 

# ----- Write data to GeoJSON
leafdat<-paste(downloaddir, "/", filename, ".geojson", sep="") 
writeOGR(subdat, leafdat, layer="", driver="GeoJSON")

And the error is:

Error in writeOGR(subdat, leafdat, layer = "", driver = "GeoJSON") :
GDAL Error 3: Cannot open file 'd:/Leaflet/County_2010Census_DP1.geojson'

Because I am a freshman in R, I searched for this problem a lot and didn't get any good answer.

I am using Rstudio R version 3.1.1(2014-07-10) on windows 7 32bit. My rgdal version is 0.9-1.

The other code in the blog runs successfully, this sentence seems to be the only difficult point.

Upvotes: 4

Views: 1129

Answers (3)

Sungchan Kang
Sungchan Kang

Reputation: 1

Even though you already have a 'd:' drive on your computer and you have permission to write to that drive, try the following:

--------------------------------

leafdat<-paste(downloaddir, "/",  ".geojson", sep="") 

> leafdat

> "d:/Leaflet/.geojson"

writeOGR(subdat, leafdat, layer="", driver="GeoJSON")

--------------------------------

Then you may get ".geojson" file on "d:/Leaflet". Change the file name ".geojson" to "County_2010Census_DP1.geojson".

Upvotes: 0

Enzo
Enzo

Reputation: 2611

I've tried to find a solution for this mysterious error for some time.

Eventually I found this post on the Gdal package errors' tickets site that clarified the problem and gave a solution.

Basically the problem is in the interface between rgdal and Gdal (Gdal changed their way to work and the latest version of rgdal hasn't watched up yet):

writeOGR() calls ogrCheckExists("foo.geojson") to check first if the file exists before creating a new dataset.
In the 1.11 version the OGR GeoJSON driver will emit an error message that this file doesn't exists, whereas previous version didn't emit an error message. 
rgdal catches this error as a fatal one and doesn't go to the writing step. This should be fixed in rgdal.
Meanwhile you have an easy workaround : add check_exists = FALSE as a parameter to writeOGR()

Therefore the following code will work:

writeOGR(spDf,'foo.geojson','spDf', driver='GeoJSON',check_exists = FALSE)

Of course if there is already a geojson file with the chosen name at the location writeOGR still fails.

Upvotes: 3

Jot eN
Jot eN

Reputation: 6416

You could create GeoJSON using leafletR package:

library('leafletR')
Your_GeoJSON <- toGeoJSON(data=YourData, dest=getwd())

Upvotes: 3

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