The OGR Simple Features Library is a C++ open source library (and command line tools) providing access to vector file formats.

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1answer
455 views

How do I get the centroid of line with OGR

Can somebody explain how to get the centroid of a feature with ogr? I have no idea what the centroid() function itself does. >>> linelyr = lineshp.GetLayer() >>> f = ...
0
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1answer
224 views

SetGeometry problems when using python/ogr

So i am trying to use the difference function and i pretty much create the new file i want but the Geometry is empty. No error is produced. any help would great! Thanks. #!/usr/bin/env python import ...
2
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1answer
103 views

Is there a quicker way of checking if a feature exists with OGR

I'm writing lot's of features to a FileGDB using OGR. The slow point in my script is checking that the feature isn't already in the Feature Class, based on the ID. Currently I'm using a function ...
0
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1answer
80 views

Is georeference the same as geotransform?

Does georeference mean the same as geotransform? If not then what is the difference?
6
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1answer
293 views

Geometry Projection Speed Test

Lately I've been using the OGR projection classes that come with ogr/gdal, but pyproj was recommended to me, so I thought I'd give it a try. To help me decide if I should make the switch, I did a ...
2
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2answers
659 views

Python GDAL/OGR: retrieved feature is NoneType

I'm doing some scripts in Python to deal with shapefiles, and I have an issue I don't understand. I'm looping over a shapefile, and I want to retrieve the geometry of each feature, but very often I ...
4
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1answer
341 views

OGR Info - Check for spatial index?

If we want to get information about a vector layer (shapefile for example) we could use ogrinfo: ogrinfo -so myshapefile.shp mylayer This returns a lot of pertinent information about the shapefile. ...
5
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4answers
478 views

How to computational efficiently check if there are any overlapping polygons in a group of polygons?

I need to do some processing with groups of polygons. If any of the polygons in the group overlaps other polygon the result is unpredictable and don't throw any error. So, I need to detect if there is ...
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0answers
96 views

Gdal/Ogr - OGRLayer.Intersection() Question

I was trying to perform intersection on two feature classes (shape file format) using OGRLayer.Intersection(), but have problems making it work with C# bindings. I am not able to figure out on how to ...
2
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0answers
330 views

ogr.GetDriverByName('FileGDB') returns None

I installed: gdal-110-1600-x64-core.msi GDAL-1.10.0.win-amd64-py2.7.msi gdal-110-1600-x64-filegdb.msi from www.gisinternals.com I can open my gdb on the command line: C:\data>ogrinfo ...
0
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0answers
77 views

Confusing offsets in shapefile written by QGIS/OGR

I think I'm stuck here. A shapefile has been updated in QGIS. Records have been deleted and those records have been marked with an asterix in the first byte of the record in the dbf file. I open the ...
1
vote
2answers
805 views

OGR Projection transformation error

I am trying to convert shapefile that was created by FME in EPSG:900913 to EPSG:3857 (I know its the same definition) with OGR in a script. datasource = ogr.Open(os.path.join(dirname,shapefileName)) ...
3
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1answer
213 views

How to sort features in a layer using OGR/Python?

How can I sort the features of an ogr layer by the values of a field? I tried naive variations of def sortlayer(ds, layer, field): lname = layer.GetName() lsort = ds.ExecuteSQL(b'select * ...
2
votes
1answer
2k views

Installing GDAL with Java Bindings (gdal.jar) on Ubuntu 12.10

I am trying to build a postgis importer for mutliple shapefiles. After geotools took orders of magnitude longer than shp2pgsql to import my data, I decided to attempt to use the java bindings to GDAL ...
0
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1answer
262 views

How to create feature LineString in a Polygon shape file layer (OGR/GDAL)?

I used below codes to create ShapeFile layer OGRDataSource *poDS, *poSHPDS; OGRLayer *poSHPLayer; ...... poSHPLayer = poSHPDS->CreateLayer (shpFileName, NULL, wkbPolygon , NULL); And I ...
3
votes
1answer
292 views

Python - OGR: Distance different than in ArcGIS

I want to determine the shortest distance between a point and a line. I use the following Python script to do so. If I compare the result of the script with the result of ArcMap's Near Analysis, I get ...
0
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1answer
222 views

Problem with showing Shape file in Geoserver

I have a number of Shape files from a customer. I can read them with both ogrinfo and QGIS. They don't have a prj-file, but I know that the projection is EPSG:3006. When I add them as layers in ...
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0answers
148 views

How to check are there any OGRGeometry (polygons) within an OGRGeometry (polygon) ?

Please see my image: I used the below statements to get Geometry: OGRGeometry *poGeometry; poGeometry = poFeature->GetGeometryRef(); Do you know how to check whether the Polygon 1 ...
0
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1answer
176 views

Can't convert geometry from Dgn file to Shape file?

I am using below codes to try convert geometry from a Dgn file to Shape file. But, I can't exit the Feature reading loop. Are there anyone know why and how to fix it ? Please download the dgn file ...
14
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1answer
754 views

How to rename field names in a shapefile from the commandline?

I need to rename the field names (attributes) in a shapefile. Is there an easy way to do this from the command line?
3
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0answers
61 views

How do I get the domain from an OGRSpatialReference?

I would like to know what the projected bounds are for a spatial reference using OGRSpatialReference. Is there some way to use the GetProjParm method to get this information? An example of what ...
13
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1answer
3k views

How do I get the pixel value of a GDAL raster under an OGR point without NumPy?

I am working on a computational model of the abundance of wild pollinators across a landscape. The model itself is complete, and I am now struggling with a post-processing step. I have my GDAL ...
5
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1answer
1k views

Python - OGR: Transform coordinates from meter to decimal degrees

I have a point in a shapefile. The shapefile is in a WGS_1984_Web_Mercator Projected Coordinate System. I want to get the coordinates of that point in decimal degrees with GDAL/OGR in Python. I am ...
1
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1answer
134 views

Creating prepared geometries with OGR from Python

Is it possible to create a prepared geometry object using the Python SWIG geos.ogr module? It seems that Shapely and GeoDjango both have this functionality, but I can't see any mention of it in the ...
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0answers
100 views

Python GDAL/OGR: check lines geometries connectivity

I'm working with shapefiles representing roads, so basically it's stored as (poly)lines. I need to perform a road connectivity checking. In other words, I want to ensure that roads meant to ...
2
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3answers
233 views

How to test if geometry is inside another?

I need to tell whether geometries from a shapefile are inside other geometries or not. For example, I want to test if there are trees (represented as points in trees.shp) inside the urban areas ...
2
votes
1answer
559 views

Batch convert OSM/PBF data

I need to import some OSM data about a region of Italy into a SHP file or Postgres DB, possibly with batch process. I already use OGR2OGR to batch import data from SHP to Oracle and Postgres and I ...
1
vote
1answer
138 views

OGR UnionCascaded gives strange lines (flat polygons)

I'm using OGR to perform a union using UnionCascaded. All my polygons have been created by GDAL polygonize which ensures that all polygons follow pixel edges and should therefore align nicely. But I ...
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vote
4answers
580 views

Get vector features inside a specific extent

The problem: I have a very large vector layer with many features and a much smaller raster layer in a defined region. I want to get only those vector features which are within the raster layers ...
7
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2answers
3k views

Generating GeoJSON with Python

Hi I want to programatically create a GeoJSON file using polygons from a shapefile but adding attributes from my own application. This is easily done for a shapefile: def ...
8
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4answers
1k views

Is there a mapping between OGR and python data types?

I'm writing a shapefile using OGR in python, creating fields on-the-fly from a python data source. Creation of a new field requires an OGR data type, is there a mapping between OGR and python data ...
3
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2answers
1k views

Is there a way to get at C's OGRLayer.Intersection() or OGRLayer.Clip() in Python?

I am working with OGR in Python and noticed that the C libraries have useful Intersection() and Clip() functions as part of the Layer class. Is there any way to get at these functions in Python? I ...
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0answers
55 views

how to get correct geo reference system for a VMap

I am new to GIS, trying to read the GeoRef System for VMap by using the following code: OGRSpatialReference *ref = layer->GetSpatialRef(); if( ref ) { QString georefSystem = ...
14
votes
4answers
7k views

How to add an attribute field to an existing Shapefile via Python

I have a Python script that adds an attribute field to a Shapefile if doesn't exist. This is easy to do with ArcGIS (graphically or via Python), but I'm looking for something that doesn't depend on ...
3
votes
0answers
106 views

traversing KML files with ogr python

i'm new to OGR processing and KML format so be gentle: i've got a series of KML files all containing multiple regions partitioning a larger area in each. i also have a series of geocoded points for ...
2
votes
1answer
286 views

OGR - Weird GeomType -2147483645 on polygon shapefile

I am trying to import a shapefile (multipolygon) in an app with ogr but I got an error about invalid geom type. If I inspect the data with ogr like this: datasource = ogr.Open("c:\\temp\\data.shp") ...
0
votes
1answer
487 views

OGR OSM-driver unable to open datasource

I want to read an OSM file with OGR. I use Version GDAL 1.9.1, released 2012/05/15. To read a SQLITE file works fine: $ ogrinfo test.sqlite INFO: Open of `test.sqlite' using driver `SQLite' ...
4
votes
1answer
458 views

Efficient computation of nearest distance for each point to closest polygon

I'm looking for a more efficient way to compute the nearest distance between features from 2 layers, in this example for each point the nearest distance to the closest polygon. Is there a more ...
2
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1answer
348 views

need help for script checking topology using ogr in python

My main goal is to create a new feature indicating if the line features intersect each other as well as if they are not connected to a feature. My problem is how to identify the intersecting and not ...
0
votes
2answers
101 views

OGR GetX() returns always zero

I am trying to get the first x-coordinates of a polygon. However I only get zero in return. What could cause that? import os, sys, gdal, ogr from gdalconst import * driver = ...
2
votes
0answers
92 views

Custom python datasource to QGIS

I'm working on a homebrew spatial feature data format, and using Python to write it's API. It occoured to me that use some tool like QGIS to display my data would be very nice to have, for debug/test ...
4
votes
1answer
984 views

How to programatically populate a shapefile field with polygon areas in OGR?

I'm trying to programatically populate a shp field with polygon areas: import sys import ogr ds = ogr.Open( 'tttttttttt.shp', update = 1 ) if ds is None: print "Open failed./n" sys.exit( 1 ...
8
votes
2answers
1k views

How to buffer a vector shapefile using ogr python?

I am trying to learn how to use ogr in python using the country and populated places datasets from http://www.naturalearthdata.com/downloads/50m-cultural-vectors/. I am attempting to use filters and ...
4
votes
1answer
228 views

How to use -lco options in gdal_contour?

I'm trying to create contours from geotiff raster with gdal_contour. My output format is Postgresql and I would like to ovewrite the existing table. When I do: gdal_contour -a 1 -f PostgreSQL -i 50 ...
2
votes
1answer
58 views

QGIS QgsOgrProvider library

I asked a question here: http://stackoverflow.com/questions/14790463/qgis-copy-layer-in-c-plugin and I was suggested to find the library which provides QgsOgrProvider::createEmptyLayer() function. Can ...
2
votes
1answer
374 views

How to debug ogr2ogr ERROR 1: Did not get at least 2 values or invalid number of set of coordinates?

I'm trying to convert a government data contour GML (http://geo.data.linz.gv.at/katalog/geodata/hoehenschichten/2011/1m-Hoehenschichten.gml) to Shapefile. It seems like it was created by FME: ...
2
votes
2answers
444 views

Using osgeo modules in ArcGIS10.1 and QGIS 1.8 python shells

This is related to an old question of mine - Issues with osgeo - qgis.core and arcpy modules Now in new versions of all the software QGIS Lisboa (1.8), ArcGIS 10.1 and pyScripter 2.5.3. They all use ...
5
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2answers
1k views

Why does this simple Python OGR code create an empty polygon?

Please excuse my ignorance...I am new to Python OGR. I am trying to create a simple square polygon and fail...this produces an empty polygon. Where did I go wrong? from osgeo import ogr driver = ...
4
votes
3answers
1k views

Python OGR: convert a point geometry into polygon

I'm writing a routine for creating the convex hull envelop around shapefiles of islands. I could read the data, extract polygons vertices into a geometry and then compute the convex hull. Now I need ...
9
votes
3answers
3k views

Get all vertices of a polygon using OGR and Python

I'm having a little trouble with the Python OGR API. What I am trying to do is get all the coordinates of each vertex of the outer ring of a polygon. This is what I have so far: import osgeo.ogr ...