Questions tagged [gml]

Geography Markup Language (GML) is an OGC Standard for expressing geographical features.

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22
votes
4answers
19k views

Using ogr2ogr to convert GML to shapefile in Python?

I am trying to convert a GML to an ESRI shapefile using ogr2ogr utility in a python script. I have successfully installed the GDAL/OGR package via osgeo but I am now struggling to find/understand ...
14
votes
6answers
3k views

What's an efficient way of detecting road junctions on a map?

I may receive maps from any source for my project, and for the C++ algorithm I'm making, it's imperative for the algorithm to know where road junctions (nodes where more than two road segments meet) ...
12
votes
5answers
6k views

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 ...
11
votes
2answers
5k views

Why can't I edit KML/GML layers?

Newbie here confused by my first experience in QGIS I have a handful of lines defining a bike route. Originally they were saved in a .gml file and later translated into .kml so they could be viewed ...
11
votes
2answers
2k views

Why does one part of GML -> KML conversion not work on Google Maps?

I have a client who wants to visualise cancer incidence and mortality rates by local/unitary authority across Great Britain. I've used Ordnance Survey data to get the boundaries of the authorities in ...
10
votes
2answers
3k views

Remove unneeded columns from geographic data file?

I have some GML data that has some unneeded columns in it. I'd like to remove these columns in order to reduce the file size. (To clarify: I mean that the file has many points in it, and each of these ...
10
votes
3answers
761 views

What does it mean “GML is an XML grammar”?

I'm trying to get my head around the theoretical side of XML and GML. The OGC web page for GML states that: The Geography Markup Language (GML) is an XML grammar for expressing geographical ...
10
votes
1answer
1k views

Is srsName of “EPSG:4326” spec compliant in GML 3.1 / 3.2?

I sometimes see srsName="EPSG:4326" in GML documents (e.g. https://postgis.net/docs/ST_GeomFromGML.html, although my particular source is not public). The intent (except perhaps for axis order that ...
9
votes
3answers
7k 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 ...
9
votes
3answers
6k views

How to write GML with Geotools?

I'd like to write GML using Geotools. Unfortunately, I can't find documentation on a GML Writer (except for this one from 2006: http://docs.codehaus.org/display/GEOTOOLS/WFS+++GML+DataStore). Could ...
9
votes
2answers
2k views

Storing GML surface in PostGIS

I'm using PostGIS 2.0.0 and would like to store a GML Surface in a way that allows calculating intersections between that surface and various points and lines. In my case, the Surface will have one ...
7
votes
3answers
6k views

How to import/export geographic information (gml or csv file) to geodatabase?

I am searching for C#/Java libraries that can import and export geographic information (gml/csv file formats) from and to geodatabases. If not yet available, is there other way to do this task? Any ...
7
votes
2answers
6k views

How to convert GML Surface to SHP Using OGR?

I have a very large .gml file with multiple layers in it. I would like to export one of these layers to .shp. It is a polygon layer (of lakes). However, I am getting the error: ERROR 1: ...
6
votes
8answers
12k views

Getting OS Mastermap data into QGIS?

I have been tasked with getting OS Mastermap topography data into QGIS system to compliment our other map layers. The data comes in .gz format. Which I am told needs to be decompressed before I can do ...
6
votes
4answers
6k views

Advantages either way between GML and Shapefiles? [closed]

After a good start many months ago of getting into GIS through QGIS, I had to drop what I was doing and did not touch it for quite some time. I am now able to get back into it and have a need to load ...
6
votes
1answer
1k views

Seeking Tutorials for GML?

Do you know any good tutorials or any resources for learning from the beginning GML? I am asking because (later) i would like to learn how to make a application schemas in context of INSPIRE.
5
votes
2answers
20k views

Converting GML to Geodatabase Feature Classes?

I have a series of XML files containing GML tags such as : <gml:posList srsDimension="2">454780.3125 525867.9375 454762.0625 525994.5625 and I need to convert these into ESRI feature classes. ...
5
votes
2answers
9k views

WFS Request Layer (GML) with Filter

Is there a solution to request the GML layer from Geoserver with filter like using bbox: http://localhost:8080/geoserver/tiger/ows?service=WFS&version=1.0.0 &request=GetFeature&typeName=...
5
votes
1answer
1k views

Why are the polygons in my GML not rendered?

I tried to view GML files from download services ( http://services.cuzk.cz/gml/inspire/cp/epsg-5514/ ) and I have a problem with viewing of polygons from layer "CP:CadastralParcel". This Layer ...
5
votes
1answer
472 views

Experience with Geoserver's GML Extension

I'd like to know if Geoserver's GML extension works (well) with GeoServer 2.1-RC2 and whether it will enable uploading of GML files via REST API.
5
votes
2answers
1k views

Adding GML files in GeoServer?

How can I add GML files to a GeoServer 2.2.2 instance? How can I edit them "on the fly" and save the results back to the server using OpenLayers? I'm adding a vector layer. in which we want to use ...
5
votes
1answer
457 views

How to convert WFS request to GML?

I have the following: var popProto = new OpenLayers.Protocol.WFS({ url: WFS_HOST, version: "1.1.0", featureType: layerName, featureNS: namespace, srsName: "EPSG:4326", ...
5
votes
3answers
591 views

Linux Tool to visualize CityGML file

I am looking for a linux program that allows me to visualize CityGML models (3D). I have tried a whole bunch so far (most of them via wine but also native ones) but I couldn't get a single one of them ...
5
votes
1answer
2k views

What is the best way to convert WKT String to GML String

What is the best way to programatically convert WKT String to GML String? Every reasonable library (at best available in some Maven repository) can be used. Till now I came up with this solution ...
4
votes
4answers
1k views

Looking for web and desktop tools with GML support

I am a graduate student and a novice in GIS field. I have few GML files that contain vector polygon data and I want to see them in a map format. The problem is that I do not have access to ArcGIS/...
4
votes
2answers
2k views

Is GeoJSON an OGC format

I am using geometries in a JavaScript page and it is best to use JSON objects rather than GML which is XML based. I heard of GeoJSON, but is it an OGC open format?
4
votes
1answer
143 views

What is the best format to encode polygons such as lakes?

I am looking for a standard format to encode polygons, such as lakes, in one file that is easy to create and common so that others can use it in different GIS systems. Every file will contain data on ...
4
votes
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 ...
4
votes
2answers
241 views

Modelling per-segment attributes in GML LineString

This is not a software-specific question, but rather a question about how to represent some concepts in a GML LineString. It has to be GML, for policy reasons. Consider a GML LineString consisting ...
4
votes
2answers
607 views

Is it valid GML if the boundary of a polygon intersects itself?

Is it valid GML if the boundary of a polygon intersects itself? E.g. I have this polygon consisting of some gml:LineStingSegment and one gml:Arc: My task is to import GML based data (german ALKIS ...
4
votes
1answer
2k views

How to convert gml:pos to latitude and longitude?

I'm trying to figure out the latitude and longitude of rail stations that are contained in this WMS feature list. I'm completely new to the GIS field, so please forgive me if I use the wrong terms ...
4
votes
2answers
2k views

How to use the OGR/GDAL configure options in QGIS Python environment

I'm looking for a solution how to use the OGR/GDAL configure options (--config) in the QGIS Python environment. http://trac.osgeo.org/gdal/wiki/ConfigOptions Setting special configure options is ...
4
votes
3answers
186 views

Trying to import Dutch Infrastructure GML using OGR GMLAS driver, but no geometries?

I have some Dutch Infrastructure GML files that I'm trying to display in GeoServer. Step 1 is to import the GML into PostGIS and while I can make it work using the OGR GML driver, I end up with a ...
4
votes
2answers
665 views

Which topology file formats are supported by QGIS?

I would like to know which topology file formats are supported by QGIS. I am particularly interested in displaying topologies encoded with TopoJSON or GML. But any other portable topology file ...
4
votes
1answer
3k views

Upload KML / GML / GeoJson to Geoserver through Rest API

What is the best option, if any, to upload a vector format like GeoJson, and or GML to Geoserver? The environment from which to upload will be a client web-application, so i cannot use curl. In the ...
4
votes
1answer
3k views

How to get a GML overlay on Google Maps?

Anyone know how to get a GML file to show as an overlay on Google Maps? To be honest I don't know my GML from my KML, or my ETRS89 from my WGS84, as this topic is completely new to me. A bit of ...
4
votes
2answers
970 views

Read an INSPIRE GML in QGIS2.0 : gml:xlink resolving

I'm trying to read an INSPIRE GML, which contains internal and external links between the elements. I saw on the GDAL site that we can set environment variable in order to load this link in QGIS (http:...
4
votes
1answer
481 views

Can GeoTools parse GML CRS definitions?

A kind of branching of this question. Soon I will need to handle GML Coordinate Reference Sysyem definitions in a Java servlet. Links: GML OGC reference. Concrete example. I know that GeoTools ...
4
votes
0answers
117 views

How to set up Geoserver app-schema feature chaining?

I am using Geoserver 2.12 with the application schema plugin to map a PostGIS database schema to the GeodesyML schema. I need to set up a WFS request that returns GeodesyML output such as: <wfs:...
4
votes
0answers
371 views

PostGIS 2.0 st_geomfromgml using LineString fails with invalid GML representation [closed]

I am attempting to insert a geometry into a table using the st_geomfromgml function. The GML is being sourced from a Geoserver WFS request. The function call looks like this st_geomfromgml('<?...
4
votes
0answers
864 views

Why doesn't the gml 3.1.1 schema validate with xmllint? [closed]

Running xmllint on the gml 3.1.1 schema fails, even though the release notes claim that this release was created to get the schema to validate using 'common tools'. There's questions about this on ...
3
votes
3answers
3k views

Loading GML data into Postgres - No geom!

I'm trying to load an Environment Agency GML file into Postgres/PostGIS using ogr2ogr. The file loads fine, all the other data is there, but when I check the table in the database there is no geometry ...
3
votes
4answers
4k views

GML Parser for C++/Java/…?

I am looking for a good parser for the latest GML (Geographic Markup Language) version in preferably: C++/Java/Ruby/... I am especially interested in reading the geometry of individual features. Does ...
3
votes
1answer
616 views

How to show one to many relationships in GML from GeoServer/PostGIS?

I am just figuring out how to use GeoServer and PostGIS. I am using the States.shp example that came with GeoServer, and I have uploaded that into a table into the PostGIS database. I have created a ...
3
votes
3answers
108 views

GML validation errors with FME

I am wondering if I am missing something. I am exporting some records from an Oracle dB to a GML2 file using FME. When I validate the resulting XML using online validators I don't find any errors. ...
3
votes
1answer
721 views

Python: shp file to GML using OGR

I am trying to convert a shapefile to GML 3.1.1 . I am using gdal 1.9.1 however the GML conversion it generates for a geometry feature is GML 2 and it also swaps the long/latitude coordinates. Are ...
3
votes
1answer
342 views

Polygon Shared Boundaries in GML

Last week I was told on a phone conference that GML supports shared boundaries in Polygon's. I have been unable to find any documenatation to substantiate the claim. Here is the situation: I have a ...
3
votes
1answer
706 views

Is there a Java library to load data from a WFS server?

I am writing a java client to display remote GIS data. I want to load data provided in GML by a WFS server. Do you know a java library I could use for that?
3
votes
1answer
2k views

OpenLayers.Format.GML.parseFeature() with GML v3 data

I have a partial GML object with the geometry type polygon. The GML version must be 3+ since the coordinates are wrapped in the gml:posList tag: <gml:Polygon srsName="EPSG:25832" xmlns:gml="http://...
3
votes
1answer
21 views

Understanding GML structure for validation

I'm failing to convert this GML v3.2 XML and I'm not sure why: <?xml version="1.0" encoding="UTF-8"?> <gml:MultiGeometry xmlns:gml="http://www.opengis.net/gml" srsName=""> <gml:...