Questions tagged [delaunay]
A prefix to help define a type of mathematical transformation, such as Delaunay Triangulation, or Delaunay Tesselation
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Creating a 3D TIN or similar 3D Delaunay triangulation in R
Background: I have topographical datasets with height information as a starting point. The endgame is to create a dataset of triangulations which I can use to import into Parasolid to be used further ...
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Calculating delaunay triangulation with two diagonal lines using ArcGIS Desktop?
How do I obtain a line output similar to a delaunay triangulation but with two diagonal lines, from a point layer containing a regular-spaced point grid using ArcGIS Desktop?
The current result is ...
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1answer
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Arcs from a Delaunay Triagulation
I am trying to generate a Cost Distance table using Spatialite.
I have several points in the table random_points for which I would like to compute the Delaunay triangulation and use the segments it ...
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Incomplete Delaunay triangulation unsing pyqgis3
I'm writing a small Qgis3 python plugin to convert polygon shapefiles to input files for a scientific model.
I therefore need to split up the polygon geometries to more simple geometries with up to 4 ...
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1answer
89 views
Match SpatialPoints to Delaunay Triangles in R
I have 2 SpatialPointsDataFrame files. I compute the Delaunay Triangles from the first shapefile (shp1) as in the code below. Then I wish to assign each point from my second shapefile (shp2) to one of ...
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Apollonius Graphs (Delaunay Graphs of Disks) in sfcgal or PostGIS?
I was wondering if there is support for Delaunay Graphs of Disks (a.k.a. Apollonius Graphs) in PostGIS/sfcgal?
A CGAL function seems to exist for this. But I can't seem to find it in the PostGIS ...
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0answers
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Polygons hull QGIS [duplicate]
I'm currently working with old french cadastre on QGIS, I've vectorised it and now I want to tile it. I've georeferenced it, but it's not sufficient for a great result. To improve the result, I would ...
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4answers
476 views
Minimum wall-thickness of a non convex polygon with holes
What is the most efficient way to find the minimal wall-thickness (value and location) of a complex, non convex polygon area including holes? See example of a polygon in blue, with the minimum wall-...
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1answer
749 views
St_delaunaytriangles polygon with holes
I'm using PostGIS to decompose a polygon with a few holes into triangles via st_delaunaytriangles. Unfortunately, it does not return the right result with holes, because the triangles being outputted ...
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4answers
813 views
Calculating Voronoi Diagrams for polygons
There are a variety of good algorithms for generating the Voronoi polygons or their complement, the Delaunay Triangulation for a set of points.
My question is simply, is there an algorithm for ...
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1answer
58 views
Query Z at intersecting point locations from a MultiPolygonZ?
I create a MultiPolygonZ geometry with ST_DelaunayTriangles().
select st_setsrid(
ST_CollectionExtract(
ST_DelaunayTriangles(
ST_GeomFromText('MULTIPOINT ...
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Constrained Delaunay Triangulations in PostGIS?
It is possible to make Constrained Delaunay triangulations in PostGIS (PostgreSQL)? I have a Polygon and I need to make internal triangulation like this:
I tried to use ST_DelaunayTriangles but is ...
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606 views
How to Create Voronoi Polygon Diagram within surrounding polygon?
I want to create a Voronoi Diagram within an outer polygon.
I want to retrieve a result very similar to this solution, which uses ST_DelaunayTriangles() to create Triangles.
Actually, it would ...
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0answers
57 views
Calculating a new attribute for a polygon based on its corners
i have a pointlayer with a real number as attribute named amount.
I want to calculate and visualize the difference of amount between neighbourhood points. So first I made a delaunay triangulation ...
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1answer
168 views
How do I create line vectors with a new ID from points in QGIS?
I have a list of stations from which I would like to create a network of lines (the one created with the Delaunay triangulation would be fine) identified by a particular ID (for example, "AB" for the ...
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3answers
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How to set up a threshold for Delaunay triangulation?
I've been working Delaunay triangulation on a set of random points inside a group of mostly linear areas (in fact, buffers around rivers).
The problem is that while the triangulation works correctly ...
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Delaunay Triangulation on labeled data
I have a table with locations and labeled data and I need to apply Delaunay Triangulation on specific labeled rows.
For example, I have some locations labeled as schools, hostels, gardens, ... and I ...
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1answer
294 views
Extracting coordinates of a triangulation from DEM data
I'm working on the succinct representation of planar graphs and now I'm trying to obtain some datasets to test my results. I saw that Delaunay triangulations of elevation data can be a good source of ...
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1answer
82 views
How to identify Sliver triangles in a TIN surface and count them? [closed]
Is it possible to count slivers in a TIN?
I generated a Delaunay triangulation surface model and i want to know how many slivers the TIN has.
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148 views
Contours from delaunay triangles
I have generated a delaunay polygon file that represents terrain data. Is there a way I can produce contours from the polygon file? I know I can convert the polygon to an Esri TIN, and then produce ...
