The geos tag has no wiki summary.
0
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0answers
18 views
GEOS: split line at point
Seeing as GEOS can node lines which intersect simply by union or intersecting them with themselves, can it (through the C API) split a line at a given point?
GEOSUnion, alas, doesn't seem to do the ...
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0answers
22 views
GEOS: How to intersect without noding?
As discussed in this question intersecting two GEOS line geometries gives a result which has also been noded.
This is very nice if noding is what you want, but is it possible (through the C api) to ...
1
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0answers
26 views
Why does polygon.intersection(complex_linestring) split the linestring and mess up Z?
I have a complex (self crossing) line with Z values which I'd like to truncate to the area inside a box. The problem is Shapely splits the line into simple (non-crossing) sections and the Z value at ...
1
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0answers
113 views
Get the distance between 2 WGS84 GEOSGeometries
I currently want to check if 2 given GEOSGeometry objects of type Point are within 100m of each other. (length flexible)
Looking at previous asked questions on this topic, most of the answers were ...
2
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2answers
176 views
Checking if a point is in a circle
I'm using shapely to check if a point is in a polygon, but I also need to check if a point is in a circle. Checking the docs, I don't see how do that...
Maybe I could create a circle?
circle = ...
2
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2answers
76 views
Why are the results different for the same point using GEOS Point.transform and Postgis ST_Transform?
I'm trying to define a default point setting for OSM layers in my application and I want users to be able to define the default latitude and longitude in EPSG:4326. What I'm doing right now is to use ...
1
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0answers
34 views
GEOS: how to access Noder functionality through the C API
All this stuff looks rather useful:
http://geos.osgeo.org/doxygen/classgeos_1_1noding_1_1Noder.html
However, from the GEOS README file:
The C++ interface should not be used directly; the geos ...
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0answers
56 views
Nearest point-line neighbour in GEOS
A harder question than the point-point one: can anyone tell me, in GEOS/C++ how to find all point-linesegment pairs closer than distance d given a set of points and a set of line segments?
I guess ...
3
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1answer
162 views
How to use GEOS/C++ to efficiently find all point pairs closer than a threshold?
Can anyone tell me how to use GEOS/C++ to efficiently find all point pairs in a dataset closer than a threshold distance d?
I suspect this might involve quadtrees or rtrees but not quite sure how ...
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0answers
44 views
GEOS: Finding all intersections with user specifiable precision
Working in C++/GEOS, I would like to find all line/line segment intersections in a set of polylines, to a user specified precision (i.e. lines that approach to within said precision are considered as ...
1
vote
1answer
167 views
Mapnik WKT rendering problem
I have a rendering problem with the mapnik GEOS plugin.
I try to input a polygon WKT definition containing floats with around 16 digits.
Mapnik however does not render these. When I decrease the ...
0
votes
1answer
182 views
python qgis.core import error caused by spatialite libraries
I have an error when trying to import qgis.core to python:
>>> import qgis.core
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ImportError: ...
8
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0answers
239 views
Solutions for fast operations on large GIS datasets [duplicate]
Possible Duplicate:
Acquiring ArcGIS-like speed in Postgis
I have been using PostGIS 2.0 for all of my GIS operations. PostGIS is an excellent GIS database, but no matter how I format my ...
0
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0answers
30 views
modify GEOS Point coordinates
I'm using the GEOS C++ library for a project, but I'm facing a problem that seems a little stupid... How do you change coordinates of a Point once it is created ? Point has a method getCoordinate() ...
4
votes
1answer
393 views
GEOS Python: Taking Union of several geometries
I am using the GEOS/OGR library in Python. I have files full of geometries that overlap, and I want to convert these to files of geometries that don't overlap.
The way I have been approaching this ...
4
votes
2answers
282 views
is there a way to tell if two linestrings “really” intersect in JTS or GEOS
In JTS (or GEOS) you can't tell if two linestrings really cross each other. The result is exactly the same whether the lines simply have a point in common but don't cross or if they really cross.
Is ...
2
votes
1answer
119 views
Converting 2D shapefile to Equal Area Projection?
I have thousands of shapefiles with coordinates in lat/long (-180 to +180 x, -90 to +90 y), that contain polygons of which I wish to calculate the area.
I'm using the Python GEOS/OGR/GDAL API. If I ...
4
votes
1answer
395 views
Wrap GEOS functionality into python
I've been looking on how to get GEOSExtractLine available in python.
I looked into Shapely source to if it was available for it, but it's not. I'm trying to wrap this funcionality into Django, much ...
2
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3answers
541 views
Accessing GEOS functions in Python
The issue:
I am using Windows 7, 64-bit operating system with Python 3.2. I must continue to use Python 3.2 because of a dependency with another API. I need some functions in GEOS that are not ...
0
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1answer
89 views
How to solve “Error creating GEOS Coordinate Sequence” in Postgis?
When I run this query:
TRUNCATE sertaozinho.apps;
INSERT INTO sertaozinho.apps (id,tipo,the_geom)
VALUES (DEFAULT, 'app' ,(
SELECT st_union(
CASE
WHEN area.cobertura = 'lago' THEN ...
