The OGR Simple Features Library is a C++ open source library (and command line tools) providing access to vector file formats.
0
votes
1answer
18 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))
...
0
votes
0answers
12 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 ...
10
votes
1answer
557 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 ...
0
votes
1answer
38 views
OGR shows no layers
I have an ESRI File Geodatabase (FileGDB) (size is 15+GB), which has over 10 layers, when I open it up in ArcGIS, everything seems to be working.
I want to move this database to postgreSQL with OGR ...
1
vote
1answer
24 views
R : convert a spatial polygon objet to spatial polygon data frame
My goal is to modify an existing shapefile by merging certain polygons.
After importing the shapefile and using the UnionSpatialPolygons command, I get the polygon outline that I want.
However, this ...
5
votes
1answer
66 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 ...
2
votes
2answers
166 views
OSR Python testSR.ImportFromEPSG(4326) returns empty spatial reference
This is empty using Python .ImportFromEPSG(4326):
import osr
#this fails:
testSR = osr.SpatialReference()
testSR.ImportFromEPSG(4326)
print testSR.ExportToPrettyWkt()
#why did the import from EPSG ...
1
vote
1answer
92 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 ...
0
votes
0answers
29 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
votes
3answers
99 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 ...
1
vote
1answer
29 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 ...
0
votes
1answer
193 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 ...
3
votes
2answers
67 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 ...
1
vote
1answer
18 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 ...
3
votes
1answer
73 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. ...
2
votes
1answer
88 views
Need help assigning values to field using OGR in python
I've got a similar question to this one How to programatically populate a shapefile field with polygon areas in OGR?, but the solution doesn't seem to be working for me. I am trying to import a ...
3
votes
1answer
488 views
How do you open shapefiles with ogr2ogr
I'm following along the D3 tutorial, and on this line:
ogr2ogr \
-f GeoJSON \
-where "adm0_a3 IN ('GBR', 'IRL')" \
subunits.json \
ne_10m_admin_0_map_subunits.shp
run into the following ...
0
votes
0answers
20 views
NYC Building Perimeter Shapefile after 2011
I've been using the following NYC building perimeter shapefile from the DOTT for some work. This file however dates back to 2010. Is there a newer one available, and if so where?
I have found this ...
1
vote
1answer
39 views
GDAL SQL syntax to add field an put values
I try to make a new field in my attribute table and put in values from another field after converting from character to integer but can't get the right syntax. I run this as shell-script in MSYS.
cd ...
5
votes
1answer
211 views
GDAL.RasterizeLayer not ported to the C# bindings?
I am trying to use the OSGeo.GDAL.Gdal.RasterizeLayer(…) from GDAL 1.9.2 and it requires some SWIGTYPE parameters:
OSGeo.GDAL.Gdal.RasterizeLayer(
OSGeo.GDAL.Dataset dataset,
int bands,
...
0
votes
0answers
30 views
Is QGIS OGR plug-in data provider (based on Postgres) limited to 500 features in layer?
I developed a plug-in based on OGR. It works fine but when I want to add a vector data (using my plug-in) I get 1449 features (with 76 columns) in my layer. Then I select this layer and load it.
...
1
vote
4answers
98 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 ...
6
votes
2answers
603 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
votes
4answers
847 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 ...
2
votes
1answer
112 views
better way to duplicate a layer using ogr in python?
I'm splitting a large shapefile into many smaller ones using ogr. I'd like to just copy all of the field and layer config information from the original. Here's how I'm doing it now:
src = ...
5
votes
1answer
162 views
Geometry errors when importing data from ESRI file geodatabase to PostGIS
When I run the following command to import by data from an ESRI fgdb to postgis...
ogr2ogr -f "PostgreSQL" -a_srs "EPSG:28355" -t_srs "EPSG:3857" PG:"dbname=tp_test user=postgres port=54321 ...
2
votes
2answers
474 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 ...
1
vote
0answers
28 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 = ...
0
votes
4answers
159 views
preferred source format for OGR conversion to GeoJSON
I'm relatively new to OGR and GIS in general. Most of the sources I look at give a choice of ESRI shapefile and MapInfo formats. I'm using ogr2ogr to convert these to GeoJSON for import into ...
12
votes
4answers
4k 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 ...
7
votes
1answer
104 views
How to rename field names in a shapefile?
I need to rename the field names (attributes) in a shapefile. Is there an easy way to do this from the command line?
2
votes
0answers
47 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
76 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
86 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' ...
0
votes
0answers
35 views
QgsVectorLayer: How to load files containing multiple layers
I’m trying to load all layers from a ZIP-file using the OGR-Dataprovider.
vlayer = QgsVectorLayer("/path/file.zip", "ZIP-Layer", "ogr")
will load only the first layer.
Any idea how to load all ...
0
votes
0answers
41 views
How to expand Ogr Sql Functionality
I'm using Ogr2Ogr for some geometric & querying operations by storing the results in SQLite files.In SQLite there are some functions I use.For that,I need to extent sql functionality.For that I'm ...
0
votes
0answers
38 views
Using GDAL/OGR exes in php
could you point me in the next logical direction? I wanted to use the gdal and run the exe commands through my web application, but have no clue what the next step should be after running the ...
2
votes
1answer
137 views
Convex Quadrilateral Polygons subdivision in equal parts using Python / OGR
Consider an irregular polygon (P) which has four vertices.
I would like to subdivide P into smaller polygons as shown here http://i.stack.imgur.com/4SKhB.jpg
In the old days I was using ArcGIS 9.3 ...
4
votes
1answer
192 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
votes
1answer
77 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
36 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
1answer
44 views
OGR CreateLayer returns TypeError
I'm trying to create a shapefile layer based on the spatial projection of an already existing raster. (Ultimately, this will be used in gdal.Polygonize to get a shape from my raster data.) However, I ...
2
votes
0answers
61 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 ...
3
votes
1answer
76 views
GDAL 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 ...
8
votes
4answers
455 views
How to build a geographic database of GPS logs?
On our aerial wildlife surveys we typically generate dozens of GPX files, and usually convert most of them into shapefiles for display in a GIS application. GPX files are a terrific way of keeping all ...
3
votes
1answer
358 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 ...
6
votes
2answers
466 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
71 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
49 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
103 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:
...
