An open geographic data format based off of JavaScript Object Notation

learn more… | top users | synonyms

11
votes
1answer
686 views

What is topojson and how is it different than geojson?

This is a conceptual question. What are the differences between these? and what are the pros and cons of these formats?
1
vote
1answer
249 views

How to write GML and GeoJSON features while retaining attributes in .NET?

I am developing a .NET project [C#] that needs to export/write features as GML and GeoJSON, including, of course, the attributes; data could queried by a database or manually entered. I checked ...
0
votes
1answer
155 views

OGR2OGR workaround for gpx-json conversion bug

ogr2ogr produces invalid GeoJSON when multiple layers are involved (http://trac.osgeo.org/gdal/ticket/3842). For example: ogr2ogr -f GeoJSON "$f.json" "$f" tracks routes For me the bad GeoJSON ...
1
vote
1answer
466 views

How to use ArcGIS 10.2 Features to JSON output in web maps?

Using the Features to JSON tool that is now available with 10.2, is there additional formatting that needs to be done to the files before they can be displayed as web maps?
6
votes
4answers
5k views

How to load external geojson file into leaflet map

I would like to load a geoJSON (polygon) file into my leaflet map. I have seen examples where geoJSON is embedded into the javascript code but I can't find any examples showing how it is done with an ...
0
votes
0answers
301 views

Continents geometry data / extracting contours of continents from country geometry

I have an ESRI Shapefile data from Natural Earth (Admin-0 Countries). I converted it to geoJSON format. There is no world or continents geometry there, only the county one. And I'd like to extract eg. ...
2
votes
2answers
369 views

How do I sort a geoJSON feature collection alphabetically by a property value?

I am trying to sort the objects in a geoJSON FeatureCollection alphabetically by the values of one of their properties. How do I get to the nested object properties with JavaScript? I have tried using ...
10
votes
1answer
2k views

GeoJson to ESRI Shapefile using ogr2ogr

I have a GeoJson file that I want to convert to ESRI Shapefile using ogr2ogr in FWTools. I tried using ogr2ogr -F "ESRI Shapefile" filename.shp geojsonfile.json OGRGeoJSON I got output ERROR ...
0
votes
2answers
201 views

Linebreak in style.Text in Openlayers 3

I have a vector layer from json, and have a style symbolizer: new ol.style.Text({ text: ol.expr.parse('name') }) In an vector layer, some of the nodes contains more than one name. I try to find a ...
2
votes
0answers
39 views

simple raster format to use in Web applications?

I'm building a Web application in which users create and edit very coarse raster data. They're assigning values to cells in a georeferenced grid. Right now I'm storing the values in a multidimensional ...
-1
votes
1answer
473 views

GeoJSON layer on Google Maps API is not showing

I am using the following codes to visualize a GeoJSOn on Google Maps API. var geojsonFeature = { "type": "Feature", ...
3
votes
5answers
488 views

How can I count overlapping polygons, resulting in a new set of polygons?

I have 100 polygons in a GeoJSON file that partially overlap each other. I would like to produce 100 new polygons as follows: The area covered by any of the original 100. This is their union. The ...
3
votes
1answer
1k views

display a choropleth map using D3 and Leaftlet

I am trying to get a leaflet map to display a choropleth map using d3. I have written this code using samples I have found however the map just displays as the black fill, not the color classes I ...
0
votes
0answers
154 views

Openlayer seems slow when zooming / panning on vector (geometry line) from geojson. Why?

I have a layer with 7 lines . when I zoom on some of the lines , the maps seems to be very slow. I thought it might be because I bring a lot of points to the client (that represents the line) aa ...
0
votes
1answer
77 views

VSI File API support in ogr2ogr

It seems that support for streaming input is wishy-washy in ogr2ogr. For example, why can I do this: curl "http://data.usgin.org/arizona/wfs?service=WFS&version=1.1.0& ...
2
votes
1answer
113 views

Which fields are standardized to describe a ShapeFiles feature?

I would like to store data into a database which is available here either as JSON or as ShapeFiles. The JSON looks something like this: { "type": "FeatureCollection", "features": [ { ...
2
votes
1answer
379 views

Programmatic conversion between GML and GeoJSON

I am modifying a .Net (C#, MSSQL) system to add some geography that I'd like to display on a leaflet map. I had originally expected to save GeoJSON directly into text strings in the DB, but after ...
1
vote
1answer
5k views

How can I change the style of marker in leaflet (from GeoJSON)?

I'm serving GeoJSON to leaflet and by default it get a blue icon marker. I'm trying to change the style so I'll be able to use the feature properties as part of the style , but no matter what I do , ...
1
vote
1answer
469 views

GeoJSON is valid according to JSONLint but jquery gives error

I have the following GeoJSON (from webservice) { "Features": [ { "Id": "1", "Geometry": { "Coordinates": [ { "Latitude": 31.2812, ...
2
votes
0answers
171 views

Show geoJSON properties in jQuery Mobile Panel

First off I'm a novice at JS so please bear with me if this is a simple task to complete. I'm currently using the stock LeafletJS popup bubble to display the properties from my geoJSON. However, I ...
0
votes
1answer
963 views

Building SQL statement in javascript and casting variables as strings

I'm working with Postgres 8.3/PostGIS which is storing some polygons. I'm writing a javascript function which will take in a parameter of a watershed id from another function. The javascript will ...
1
vote
1answer
773 views

GeoJSON in Leaflet

I'm just starting to work with leaflet and have a basic question about showing a geoJSON file. First, I found this excellent article with example code: http://bl.ocks.org/lxbarth/4019660 However I ...
2
votes
3answers
387 views

Is GeoServer getting coordinate output in GeoJSON WFS wrong?

When I do a WFS request to GeoServer and specify the SRS like this: http://myserver.com/geoserver/wfs? service=wfs& version=2.0.0& request=GetFeature& ...
2
votes
0answers
221 views

R, GeoJSON and Leaflet

I recently learned about leafletjs.com from an R-Bloggers.com post. One such tutorial that I would like to achieve is to create interactive choropleth maps with leaflet. I have been using the rjson ...
3
votes
3answers
341 views

Is it possible to check incoming GeoJSON to see if any of the features are identical to existing ones before adding to map?

I am working on a Rails/PostGIS app and doing a typical ajax call to retrieve GeoJSON within the map viewport bounds. Whenever the map is shifted or zoomed all of the markers are removed and then ...
0
votes
2answers
796 views

How to create multiple polylines using an external geoJSON file using Leaflet?

I'm starting with Leaflet and I'm using some georeferenced information collected from twitter. I already manage to load an external geoJSON with some points. But now I wan't to draw some connections ...
2
votes
2answers
803 views

How to determine intersection between geojson feature and given coordinates?

I'm overlaying a leaflet map with features of geojson, fetched with d3 and added as SVG elements to the DOM. My geojson contains too many features to render at once, so my goal is to add to the map ...
0
votes
0answers
90 views

Is there a big (if any) performance difference between Geoserver SQL Layer and OpenLayers geojson Layer?

I have a table with multiline geography items in SQL Server 2008 (Routes). I want to show them on OL Google Map but I'm having trouble creating SQL Data source in geoserver (something related to ...
1
vote
1answer
107 views

Can a GeoJSON GeometryCollection contain another Collection?

From a reading of the spec it seems that a GeometryCollection is a Geometry and can contain geometry objects? But I want to be sure that this is really allowed before I file a bug report.
3
votes
4answers
1k views

Display GeoJSON layer on top a SVG image instead of a map.

I'm very new to GIS, so hope this is the correct place to ask. Not sure if this will even be possible. This is what I want to achieve: In short, I want to display a set of polygons, lines etc. in a ...
3
votes
0answers
348 views

What are the default units of elevation/altitude/z in GeoJSON?

The GeoJSON spec says "The default CRS is a geographic coordinate reference system, using the WGS84 datum, and with longitude and latitude units of decimal degrees". It doesn't say seem to specify ...
0
votes
2answers
318 views

PHP PostGIS to geoJSON missing required parametar error

I'm using this PHP PostGIS to geoJSON script: https://gist.github.com/bmcbride/1913855 But I keep getting this error: 'missing required parameter: geotable' This is my code: # Retrive URL ...
1
vote
2answers
290 views

Can't read returned geojson

I've got a function that takes an Openlayers mouse click and puts the click location into a SQL statement which then gets passed to a JSP script which runs the SQL statement on the PostGIS database ...
1
vote
1answer
199 views

How do you make a function for changing projection with proj4js in Openlayers?

I have included Proj4js in OpenLayers. I would like to create a function (so I can use a make a button). To change the projection of my map. I have included in javascript Proj4js.defs["EPSG:54008"] ...
0
votes
2answers
114 views

How do you get all info from GeoJSON layer in Openlayers?

In OpenLayers I have added a GeoJSON layer (of the world) and created a simple infotool. The GeoJSON layer contains multiple features for some countries. If I click on a country I only get one ...
1
vote
1answer
211 views

OpenLayer and not well formed Json

I am learning to use GeoExt and OpenLayers, and I want to reproduce one of the examples given at the geoExt website. The script call a GeoJSON containg the position of Alp summits. I downloaded it via ...
0
votes
1answer
882 views

Loop over features of a GeoJSON object from CartoDB

I have just little knowledge about HTML and JavaScript. Nevertheless I was playing, copying and pasting around with Leaflet and CartoDB. I want to display the features GeoJson in a table. This is ...
1
vote
2answers
338 views

Looking for a GeoJSON describing the french departments

Is there any place where I could find a GeoJson describing the borders of the french departments, or do I have to convert a .shp file?
1
vote
1answer
460 views

Attribute editing in QGIS on geoJson file

We have vector files in the format of geoJson files. We need to keep it in geoJson format as it is picked up by mobile devices via Restful services. The problem is we want to change the attributes of ...
0
votes
1answer
254 views

geojson -> topojson : no output

Trying to convert my geoJSON file into topoJSON so I downloaded topojson from npm and followed the instructions on gis.stackexchange Convert GeoJSON to TopoJSON basically the same as the topoJSON ...
-2
votes
1answer
63 views

Render specific vector data from database with openlayer

I want to render some data on a map. They are stored as points in my database (postGiS), each one is associated with a name. I want to render points with the same place name in the same color. ...
3
votes
2answers
2k views

Is there any efficient way to convert Geojson to WKT?

I want to use ST_GeomFromText() to load vector data to PostGIS. However, I don't know how to convert from Geojson type to WKT. N.B. I know I can use OGR2OGR to upload the geojson directly, but I just ...
1
vote
1answer
940 views

How to get correct format of coordinates for export to geojson from QGIS?

I've created a custom map in QGIS with a few shapefiles. I'm using leaflet.js to render the map and the shapefile points and everything lines up correctly. The CRS is set to 4326. When I export the ...
0
votes
0answers
559 views

How do I add elevation data to a GeoJSON line from a GPX file?

I understand that elevation can be added as an optional third value in Coordinates (lat, long, elev) in a geojson file, but I can't find a way to actually do that from a gpx file. I've used ogr2ogr to ...
0
votes
1answer
566 views

PostGIS error reads “Geometry has Z dimension but column does not” [duplicate]

I try to store a polygon in GeoJSON format into my PostGIS table. Both are using the CRS EPSG:3857. This is how the polygon is defined. Note that I put in some whitespace to make it more readable. { ...
7
votes
3answers
3k views

How to insert a GeoJSON polygon into a PostGIS table?

I need to insert a polygon from GeoJSON to my PostGIS table. This is how the SQL query looks like. INSERT INTO tablename (name, polygon) VALUES ( 'Name', ST_GeomFromGeoJSON ( { ...
3
votes
3answers
1k views

How to add a polygon from PostGIS ST_AsGeoJSON into Leaflet?

I try to use the following function to add polygons to my Leaflet map. function polygon(geojson) { alert(geojson); // alert for testing layer = L.geoJson(geojson); layer.addTo(map); } ...
2
votes
1answer
1k views

Conversion from Shapefile to TopoJSON format results in incorrect map when rendered using d3js

I am trying to build a map of Canada showing FSA boundaries using d3js. I got shape data from Statistics Canada ...
2
votes
1answer
275 views

Kartograph Open Street Maps

Firstly, congratulations to Gregor Aisch for creating such a wonderful library, thank you! I am having a little trouble rendering an svg from some osm data. I downloaded the Sweden transportation ...
3
votes
2answers
133 views

Performance loss for OpenLayers EPSG transformation? Storing GeoJSON coordinates in lat/lon or in native map projection?

For a project the map projection is EPSG:32468 (tiles). On top of the map, two or three GeoJSON LineStrings should be displayed using OpenLayers. Each LineString has about 1500 coordinates. ...