Questions tagged [geojson]

GeoJSON is a geospatial data interchange format based on JavaScript Object Notation (JSON)

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Spatial Data from Postgis to Java/REST with RestEasy + Jackson

I'm developing an application where I take a route from google maps, save it in postgresql/postgis. I'd like to take this route (LineString geometry) and send it back to Google Maps. I already can ...
2
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1answer
2k views

How to visuilze PostGIS data in GeoJSON format with PHP

I need to visualize PostGIS Geometry column as an overlay of a Leaflet tiled Map. I started a question here ,but didn't get any simple and satisfied answer. So I am starting this question. I got an ...
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1answer
40 views

GeoJSON - Resymbolize without redownloading?

GeoJSON served via GeoServer to OpenLayers. Simple question - Is it possible to apply a new styleMap without redownloading the data from the server? I am currently using the following, but am ...
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1answer
881 views

Attribute extraction from GeoJSON to symbolize - OpenLayers

Loading polygons from geoserver via OpenLayers using GeoJSON. My plan is to symbolize using attributes in the GeoJSON. I am struggling to access the attributes. Any insight appreciated: The ...
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5answers
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GML, KML, GeoJSON - Speed rendering 3109 polygons?

I am working with Geoserver, serving U.S. Lower 48 counties to openlayers (3109 polygons - lots more vertices). The counties are loaded into a postgis database. I am curious about developer ...
4
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1answer
1k views

How to avoid corrupt geometries when translating between TopoJSON and GeoJSON?

I'm trying to display some geojson vector features on a leaflet map. The size of my GeoJSON is too big (25.4mb of data, 8.47mb gzipped), so I'm trying to use a TopoJSON format to reduce the size ...
3
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1answer
930 views

ogr2ogr from Postgres to GeoJSON missing crs key

I'm using ogr2ogr to convert some OSM data for Greenland (not really important for the question), from a PostGIS database to a file containing GeoJSON. The problem is that the GeoJSON gets written ...
6
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1answer
2k views

Real time positioning of vector features using database

I am a newbie in GIS and want to implement something like a vehicle tracker wherein I will get a series of coordinates in a database. I have no idea how to go about it, I mean what should my process ...
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2answers
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Trouble with GeoJSON in HTTP GET Request

I using a Vector Layer with the HTTP protocol to request GeoJSON from my web server, and am trying to get this GeoJSON to display on my map. The GET request appears to be working correctly, as I can ...
2
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1answer
302 views

Which OpenLayers.Protocol should I prefer which design patterns provided at?

At our scenario, there is a server which stores the feature info (coordinates, properties, etc) into a SQL database. Google Maps are used for a layer. The geoJSON data format are used for ...
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1answer
2k 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 antemeridian,...
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1answer
1k views

GML and GeoJSON vector layer can not display in Firefox and Chrome

I have following codes. It works perfectly in IE (GML and GeoJSON vector layer was loaded), but not in Firefox and Chrome without any errors noticed. Please help me to fix this problem. Here is the ...
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1answer
2k views

What is generally faster in OpenLayers: WMS or GeoJSON?

I work both with WMS (connection with postgres) and GeoJSON in OpenLayers. I have the impression that a WMS is faster when more feature need to be loaded. And I have the impression that GeoJSON is ...
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3answers
748 views

GeoJSON generator with OpenLayers support

Is there a service that allows me to draw on an OpenLayers map, and see the resulting GeoJSON?
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2answers
10k views

How to get GeoJSON features using OpenLayers?

Can anybody explain how to get geojson features .Can somebody show way to get attributes from geojson text. OpenLayers.ProxyHost = "/gt/proxy.cgi?url="; var lon = 5; var lat = 44; var ...
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2answers
1k views

Go to the URL on click with GeoJSON

I'm using Leaflet API and geojson. I defined a function which zooms to the feature when clicked: function zoomToFeature(e) { map.fitBounds(e.target.getBounds()); } function ...
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0answers
536 views

translating and scaling viewport to fit geojson map in D3js

I am trying to load a map of Rio de Janeiro (Brazil) in GeoJson for with D3js the code and the map is here: https://gist.github.com/4157853 I can open the map normally with Qgis, but with d3js ...
6
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1answer
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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 ...
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3answers
14k views

How to create a GeoJSON that works with D3?

I'm simply trying to convert a .shp file to a geoJSON format using: ogr2ogr -f geoJSON output.json input.shp After executing the command nothing seems to be wrong. Here's an excerpt from the output....
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1answer
808 views

How to validate whether the BBOX strategy works successfully?

I want to send requests to our feature server that asks only data within the viewable map extent. So I've used BBOX strategy and HTTP Protocol as following code. mVectorLayer = new OpenLayers....
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0answers
2k views

searching GeoJSON features

After googling for many days and reading the OL documentation, I don't understand well how the filterToParams in OpenLayers.HTTP protocol should work, what I'm trying to do is to find and display the ...
3
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1answer
5k views

Mapping x, y pixel coordinates to latitude and longitudes on the WGS84 datum

Apologies in advance for the long question, I am fairly confused at this point and I figure if I show my thought process any flaws early on in the piece can be more easily pointed out. I have a grid ...
6
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1answer
2k views

Change Layer name when converting from GeoJSON

I am converting GeoJSON files to other formats (including KML) using ogr2ogr. As you may know, there is no field in a GeoJSON file to specify the name of the layer, causing every conversion to have ...
2
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2answers
2k views

Exporting OpenLayers.Layer.WMS to GeoJSON / KML

I'm looking the way to exporting an especific region of a WMS layer to some XML format (GeoJSON, GML, KML) using OpenLayers and Geoserver. I've found how to export features objects with OpenLayers....
2
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1answer
91 views

Which conditions does the geoJSON file read from the server in?

I've added an alert to the function myReadFunction in order to detect function calls. As according to my observations, the function readMyFunction is called sometimes while I have been navigating on ...
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2answers
1k views

How to use GeoJSON from Geoserver?

Please help me on how can get my map from Geoserver. I want create my country web but I can nott see it in my browser but I can see in Geoserver. Please help me I am very new openlayers and Geoserver. ...
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1answer
646 views

How to publish my map from geoserver [duplicate]

Possible Duplicate: How to develop a map with layers in Geoserver? I'm trying to create a simple map for my city. I have a shape file my city, but I can't create on the web. I tried to take from ...
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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' ...
2
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1answer
2k views

Polymaps Project + Geojson + D3

How are you doing ? I am Mehul Nahar working on a project which is similar to http://www.tableausoftware.com/learning/examples/gpa-analysis. I have used Polymaps platform, where I have used cloudmade ...
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1answer
1k views

How to render GeoJSON tiles from Tilestream for polymaps?

Have been using polymaps successfully till now. Need to generate GeoJSON tiles for Canada Provinces. Found Tilestream and got it working with Tilemill. Is there a way I can make Tilestream hand ...
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2answers
2k views

Convert ArcGIS Javascript api Geometry Object to GeoJson [duplicate]

Possible Duplicate: How to convert ArcGIS Server JSON to GeoJSON? How to convert ArcGIS Javascript api Geometry Object to GeoJson using Javascript?
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1answer
822 views

Draw svg-circle on a coordinate with polymaps

I'm making a tracker system which uses polymaps to display a satellite image. The code is copied from the bing-example on the website of polymaps. I now want to periodically call an update function ...
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1answer
1k views

Select independent objects using GEOJson on Openlayers

I'm working with OpenLayers and loading a couple of GEOJson files which works perfectly. Now I want to be able to select individual components of the GEOJson file. As for example if I have more than ...
2
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1answer
677 views

Vector layer won't move as window resizes in Chrome

I have a GeoJSON layer that I am treating as a javascript object in my openlayers map. When I use IE or Firefox, everything works fine. However, in Chrome, as I resize the window, the GeoJSON layer is ...
4
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2answers
1k 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 "...
3
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2answers
1k views

how we create line between two cordinates on polymap?

I am working on d3 and polymaps, I plot map and create circle on the given latitude and longitude which retrieves from the JSON file but now I want to connect those circles with line. I tried to do it ...
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1answer
2k views

Alternate colors of GeoJSON linestring segments in OpenLayers?

I am rendering a vector linestring via GeoJSON on top of an OpenLayers map. I'd like to alternate the styling between two slightly different shades of blue, such that the colors alternate from one ...
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2answers
2k views

Generating GeoJSON tiles from GeoDjango - basic overview?

I'm working with the glorious PolyMaps and I want to build a map similar to the population example. I understand that this needs GeoJSON tiles. I have a GeoDjango database, with a bunch of County ...
6
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1answer
2k views

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

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
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2answers
2k 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 ...
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0answers
91 views

How to load GeoJSON files directly onto QGIS? [duplicate]

Possible Duplicate: Plugin or script to get QGIS to display geoJSON in a layer Is there a way to do this? Or is there a way i can put it onto PostGIS and then load it onto QGIS? I actually used ...
3
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1answer
3k views

OpenLayers & GeoJSON files

After some hunting, it seems that if I have an a geojson file, I NEED the data and map to be on a server in order to view this in OpenLayers because of the protocol class. I saw an example where I can ...
7
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1answer
406 views

Representing a TIN in GeoJSON

Regarding the GeoJSON representation of a TIN, are there any specifications or existing implementations I may not be aware of? You could probably hack one together using the multipolygon feature ...
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0answers
224 views

How to show an array of 2d points/polygons in Polymaps (Cartesian coordinate system)

I need to display these 2d points/polygons (Cartesian coordinate system) on Polymaps with GeoJson layer. I do not use the other layers. Do I need to convert xy coordinates to the lat lon? If so, how? ...
2
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1answer
2k views

Openlayers dynamic filtering/styling of geojson layer

I'm working with Openlayers and overlaying a geojson file representing species type over OSM. I have an HTML form that allows users to select a species type and I then need to filter the geojson layer ...
4
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1answer
1k 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 ...
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1answer
698 views

How to update GML layer without reloading local file?

I set up a GML layer with local GeoJSON file as data source: veclayer = new OpenLayers.Layer.GML("vector", "localfile.json", { format: OpenLayers.Format.GeoJSON, strategies: [new OpenLayers....
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1answer
357 views

Polymaps / Tilestache tiling grid mismatch

I have set up a basic PostGIS / Tilestache / gunicorn / nginx / Polymaps test environment, rendering my dataset from PostGIS to GeoJSON and shipping it out to be rendered in Polymaps. That works ...
24
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3answers
9k views

How to store lines and polygons in JSON documents?

Looking at the increasing NoSQL movement and considering that databases like MongoDB offers a new perspective in flexible data storage for GIS. What is the best way to store lines and polygons in ...
8
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3answers
2k views

What is the intended Behavior of -skipfailures in ogr2ogr?

I am trying to run ogr2ogr to convert some geojson to shapefile. All is good until any of the geojson features have an invalid geometry (for example, the coordinate array of point geometry is empty). ...