An open geographic data format based off of JavaScript Object Notation

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6
votes
4answers
678 views

How to use Leaflet to efficiently show parts of a massive dataset?

I keep seeing non-GIS web developers running into this problem, and I'm not sure what the solution is. There is some dataset of thousands of items. We want to show a map to the user, with the ...
6
votes
3answers
695 views

How to generate image tiles from custom geo data for use with Leaflet

Migrating a webapp from Google Maps API V3 to OSM + Leaflet, which displays custom data that consists of lots of lines and points, on a background map. When this custom data is drawn by Leaflet on ...
6
votes
1answer
263 views

How do I represent the whole Earth as a Polygon?

This is related to determining the interior of a Polygon. My difficulty is that if I specify a Polygon covering the Earth going from East to West, it will still have a boundary along the ...
5
votes
3answers
3k views

How to convert geoJSON to python objects?

New to the site, and to geoJSON, and to python. My goal is to read in a file with geoJSON data, and use it to generate shapes to be used in an application that is using python scripting. Python has ...
5
votes
3answers
1k views

Can we merge shapefiles with different geometries (point and polygon) to get a single layer which shows both geometries?

I want to merge two shape files in which one is of point geometry type and other is polygon type in order to get a single layer containing both points and polygon in a single map.
5
votes
1answer
3k views

leaflet geojson coordinate problem

I just started to play with leflet/geojson a little. But my coordinates are not rendered properly and I have no clue what is going on. My coordinates are: 52.23943, 4.97599. They work correct with ...
5
votes
2answers
2k views

GeoJSON java library

I am creating a Java web service that receives GeoJSON. Does anyone know a java library to manage GeoJSON?
5
votes
3answers
823 views

Is there a API which return the geojson data for a countries borders?

Is there a simple free REST API where I can send the name or code of a country and get in return geojson data which highlights it's borders ? I'm writing an application where I will have a changing ...
5
votes
1answer
222 views

Is there a free dataset of historical geocoordinates of ancient cities and places?

Is there a freely available dataset (csv, geojson, topojson, etc.) with geocoordinates of ancient cities, for example of the Roman Empire? Ideally with additional information like population size? ...
5
votes
3answers
2k views

Interacting between Openlayers and Python

I have a openlayers website like this one that gives the user the ability to draw polygons and then creates a GeoJSON file. I want to process this GeoJSON with a python script. The python script ...
5
votes
2answers
4k views

Parsing a GeoJSON file with jQuery

I'm trying to iterate through a GeoJSON file (below) and eventually populate an array with a few attributes within "properties". I keep coming up short working through various examples I can find. Do ...
5
votes
1answer
276 views

Conventions for returning GeoJSON via an API

I have a queryable API that returns one or more GeoJSON FeatureCollections. Currently the response looks something like this: { "success": { "data": { "layer1": {"type": ...
5
votes
2answers
1k views

How to generate one geojson file from several rows in Postgres/PostGIS?

I have a table with geospatial objects, in particular, polygons. I know that I can generate from one row a geoJSON string using ST_AsGeoJSON(http://www.postgis.org/docs/ST_AsGeoJSON.html). But I would ...
5
votes
2answers
1k views

OGR merge shapefiles of different geom type into a single GeoJSON feature collection

I'd like to merge shapefiles of different geometry types into a single geojson feature collection, but OGR says it doesn't support update of GeoJSON files: $ ogr2ogr -f GeoJSON -t_srs crs:84 -lco ...
5
votes
1answer
734 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 seem to specify what ...
5
votes
2answers
362 views

How can I setup a simple web mapping system?

I'm new to mapping and GIS and I'd like to setup a mapping system to display informations on a map, I think the following could work but I'm not sure how good it is.. 1- I store my data (lat, lng ...
5
votes
2answers
344 views

Leaflet: How to enable pan & zoom while GeoJSON still rendering?

I've overlaid a huge GeoJSON geometry on top of my Leaflet map, covering about 20 countries' borderlines (about 1,5 million vertices) using "L.geoJson". Each time I zoom in/out, the computer has to ...
5
votes
2answers
3k views

Create multiple vector layers by reading a GeoJSON file once in OpenLayers

I am a begginner to OpenLayers, and my question is about making things more efficient. My work is about displaying time-dependent weather elements on several point locations on the map. All these ...
5
votes
1answer
701 views

Leaflet - Change style on click

I am beginer with Leaflet library and I am facing an issue with a geojson. I have an extern geojson file (points) and I would like to display a circle for each point coordinates and get a bigger ...
5
votes
2answers
1k views

Large loads geojson from mysql to leaflet?

I have a mysql database with +25K rows including geometry and other attributes. Using a mysql2geojson php script I then added it to a leaflet map. It is super slow now, what can I do to boost the ...
5
votes
1answer
850 views

Exporting Arcgis Online content as georss or geojson? [duplicate]

There are number of sites talking about how to add a georss feed to an ArcGIS Online map (see silverlight and flex examples from esri_webapi), but I haven't located anything about exporting a georss ...
5
votes
1answer
985 views

Working examples of Leaflet/Polymaps with GeoJSON tiles generated from Tilestache using Shapefiles?

I'm looking to create choropleths using GeoJSON tiles generated from ESRI Shapefiles by TileStache(or similar), in either Leaflet or Polymaps. So far reading and drawing GeoJSON from both Leaflet and ...
5
votes
1answer
1k views

Why are GeoJSON coordinates different exported from QGIS vs. ogr2ogr?

I have a shapefile with a Google Mercator projection (900913) that I need converted to GeoJSON. I need to do this on a regular basis amongst other things so I wrote a shell script to do it using ...
4
votes
2answers
3k views

Convert GML to GeoJSON

I have downloaded a GML file from Statistics Canada and would like to convert it into GeoJSON to use parts of it in a D3 visualization on the web. However, I did not find a converter that would do ...
4
votes
2answers
2k views

How to merge TopoJSON features?

I currently have a coordinate based map of the US and it's states for topojson (https://github.com/mbostock/topojson). The coordinates are a JSON array (as topojson works), data looks like this: ...
4
votes
3answers
3k views

Online WKT and GeoJSON viewer

I once found a great but simple webpage that has a drop down with several text-based GIS formats such as GeoJSON and WKT, and a text box to copy/paste your data. The feature is then drawn on a world ...
4
votes
1answer
549 views

Is there an XML equivalent to GeoJSON?

In my web application, I am retrieving geospatial data from a server backend (Java) to the browser frontend (JavaScript). I am considering two options of how to serialize the data in this ...
4
votes
3answers
3k views

MySQL to GeoJSON - Formatting Issue

I'm trying to make a select on a mysql table and then write it out to a geojson file. I'm getting close but there are a few issues. Here's what I have so far: <?php require("dbinfo.php"); // ...
4
votes
4answers
3k 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 ...
4
votes
1answer
10k 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 , ...
4
votes
2answers
508 views

Where can I find GeoJSON resources files?

I'm looking for demographic information and various things, and most of the time data are available as CSV (my application use geoJSON format). Shall I encode the CSV to geoJSON or is there a ...
4
votes
2answers
1k views

Beginner needs suggestions on map clicks and geojson

I'm a beginner with programming, and javascript. I went to the FOSS4G-NA conference and was very inspired to learn more. I'm trying to learn PostGIS, and have come across a very useful tutorial for ...
4
votes
2answers
2k views

Reproject GeoJSON in OpenLayers 3

I'm basically trying (and failing) to replicate this in OpenLayers 3. I've set up a fiddle here: http://jsfiddle.net/vu8ecy8v/5/ I'm under the impression that OpenLayers will reproject a GeoJSON ...
4
votes
2answers
1k views

GeoJSON/GeoCouch questions from a newb [duplicate]

I am new to JSON and GeoJSON and would like to start to use this but I am a little confused about some things. Perhaps you can help me out: 1) Is there a GeoJSON validator out there? 2) Is the text ...
4
votes
2answers
76 views

Big data sets and challenges using the Leaflet client

I am using Leaflet to present around 90.000 data points. My test code is generated using the plugin QGIS2leaf in QGIS 10.10.1. I am using clustering and reviewing the code I can see that this is ...
4
votes
1answer
138 views

Leaflet JS add GeoJSON shape as a hole in a polygon

I have a dataset which already contains geojson. I can add it to my map with the following line of code. L.geoJson(data.geojson).addTo(map); And I get this But I want to achieve this, where the ...
4
votes
1answer
3k views

Custom marker/icon based on attribute data in leaflet/geojson

I would like to add different icons to my leaflet map based on attribute data. My layer is a geojson layer, it is coming from geoserver with jsnop. I can see my data with the default marker, but when ...
4
votes
3answers
457 views

Adding Properties to GeoJSON File

I have a GeoJSON file of the country of Haiti with the administrative boundaries for communes (i.e. counties). Here is the file: ...
4
votes
1answer
210 views

Day and night zone layer for Leaflet

I'm working with Leaflet and I'd like to show the day and night zones adding a dynamic layer to my map. I was thinking to add a static layer with some transparency and make it move every x minutes but ...
4
votes
1answer
6k views

How do I get GeoJSON data from GeoServer into show up on my Leaflet map?

I'm trying to create a simple "Green" map for my city. The idea being that it is a website with a map and layers you can turn on and off. I am serving the data through GeoServer and am using GeoJOSN ...
4
votes
2answers
2k views

Using QGIS, how can I add a bounding box attribute?

I have a shapefile where I am exporting the features to GeoJSON objects with ogr2ogr based on a simple where clause. One thing that I would like to be included in the GeoJSON object is the 'bbox' ...
4
votes
1answer
70 views

Truly lossless TopoJSON / keep all coordinates in TopoJSON

I'm displaying GPX traces on a Leaflet map. I'm using TopoJSON to drastically reduce file size, which works pretty well. My problem is the following : I want to be able to display altitude and ...
4
votes
1answer
1k views

SQL query to have a complete geojson feature from PostGIS

I would like to get a geojson feature with properties from PostGIS. I have found an example to have a feature collection but I can't make it works for just a feature. so far I tryed to modify the ...
4
votes
2answers
1k views

Is it valid to have a properties element in an geoJSON featureCollection?

Is it valid to have a properties element with a featureCollection-element as parent? This is, according to geojson.org valid: { "type": "FeatureCollection", "features": [ { "type": ...
4
votes
1answer
219 views

Dump a GeoJSON FeatureCollection from Spatialite query with Python

Given a Spatialite database, holding a table with a geometry column and some other attribute columns. I want to query that table in a Python script and get a GeoJSON FeatureCollection string in return ...
4
votes
1answer
279 views

Leaflet: Change point icon (geoJSON) on click and change back when clicking another point

I would be very grateful if someone could help me with this. I have a geoJSON (10 points) that is drawn using an icon. I want to change the icon when I click on one of the points and then I want to ...
4
votes
1answer
432 views

Leaflet: how to change default style on a point GeoJSON Layer?

I need to change style on a point GeoJSON layer in a Leaflet map. I'm using the following code: function onEachFeature(feature, layer) { if (feature.properties && ...
4
votes
2answers
932 views

get map tiles for a polygon

Based on this tutorial, I can easily find out a tile for a point. But is there an algorithm to find all tiles that are covered by a rectangle or lineString or by any other feature? I would greatly ...
4
votes
1answer
242 views

Consume geojson web service in ArcMap

I need to consume data from a REST endpoint that returns features in geojson format within a model in ArcGIS 10.2. Is there a way to access a URL instead of opening a file? If there is no way to ...
4
votes
4answers
2k views

Convert Sql Server Spatial data to GeoJSON & plot on map

I have a sql server table with Geo spatial data. An example of row would be (with Column names): type: streetline code: 231001 geog: 0xE6100000011 ........ Centroid 0xE61000000C....... geom: ...