Questions tagged [voronoi-thiessen]

Thiessen polygons are polygons (generated from a set of points) whose boundaries define the area that is closest to each point relative to all other points. Thiessen polygons are mathematically defined by the perpendicular bisectors of the lines between all points and are created by means of a triangulated irregular network (TIN) structure.

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How to delimit point distances in ArcGIS for Desktop per Thiessen polygon

I have 2 shapefiles. The first set contains x,y coordinates for 1100 hospital locations. The second pair contains x,y coordinates of about 7000 villages that are served by the hospitals. This means ...
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How to use ST_VoronojDiagram for points that are almost aligned?

I am trying to use the spatialite ST_VoronojDiagram function on a table containing four 4 points that are almost aligned: (1.01 2.02, 2.02 3.03, 10.01 10.02, 11.01 11.02). I wrote the following script ...
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R: Voronoi tesselation from long/lat data?

I want to create a SpatialPointDataFrame and Voronoi Tesselation from my .csv data downloaded from EPA, available here: http://uloz.to/xboQc7cu/no2-calif-csv I convert my data in SPDF format in 2 ...
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What is the difference between Create Thiessen Polygons tool (ArcGIS) and Voronoi Polygons tool (QGIS)?

Is Thiessen polygons the same thing as Voronoi polygons? I am using ArcMap 10 and also QGIS 2.4 and I would like please to know the exact difference (If any) between the two methods.
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Thiessen Polygon delineation within a Feature

I am trying to create Thiessen (Voronoi) polygons, based on points within a defined shapefile extent. The output should be inclusive to the feature. The output I receive now is the rectangular area ...
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195 views

voronoi / thiessen different CRS

I have the following problem in QGIS: I try to create voronoi polygons based on a shapefile (points; standard WGS84). The newly created voronoi polygons layer seems to be ok for the WGS84 CRS. But ...
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640 views

Where can I find the version of scipy python package used in QGIS Lyon 2.12?

I am using QGIS Pisa 2.10. I want to use the Voronio class of scipy.spatial in QGIS python console. QGIS Pisa has 0.11 version of scipy package. This package doesn't have Voronoi class. I even tried ...
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The drawing of Thiessen/Voronoi polygon boundaries - are the bisecting lines truly perpendicular?

I am concerned with how QGIS (version 2.8.1) and ArcGIS (version 10.0) draw "perpendicular bisecting lines" when Thiessen/Voronoi polygons are created. When using either program to create these ...
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Calculating area of intersection of polygon to another layer in ArcGIS for Desktop?

I am very new to GIS, especially ArcGIS. I am currently using ArcGIS 10.2, and I have 2 layer, namely the purple feature map(this layer is an import from arcgis online, it doesn't seems to be an ...
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Create Thiessen polygons using spatially weighted averages? [closed]

I have to create Thiessen polygons with the spatially weighted averages for specific contaminate concentrations from different borings. I have the Thiessen polygons created but this only shows me the ...
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Thiessen polygons modified for slope

I seem to recall to have read about Thiessen polygons which, instead of having straight boundaries, had some irregularly shaped sides. That was since those polygons were actually taking into account ...
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How to use Delaunay triangulation in QGIS?

I have to create a Thiessen polygon for a site in New Jersey and all I have right now is the concentrations from samples we took in the area. What else do I need and how do I input it into QGIS to get ...
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Split a polygons into many polygons based on points using ArcMap

I have: A polygon feature that is a national park boundary, A multi-point feature that are security guard posts (number = n ) of the same park. I want to divide the national park area into 'n' ...
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Efficiently generate Voronoi layers in qgis via Python

The following python commands both appear to function when called in qgis 2.6 to generate Voronoi diagrams: processing.runalg("qgis:voronoipolygons", pointLayer, 1, None) processing.runalg("grass:v....
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Creating polygons using mask layer?

I looked at this question, but it only answers part of my problem. I want to create Thiessen polygons based off of the green points within the blue polygon boundary ONLY. I've set the Processing ...
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Interpolation from isolines vs Thiessen (Voronoi) polygons interpolation

I'm currently studying GIS and have come across a question in an assignment that I just can't answer. I've been googling my brains out for the last few hours and got nowhere... here goes... Identify ...
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How can I put Voronoi/Thiessen polygons on Google Maps for free with no programming knowledge?

The only thing anywhere close to what I describe in the title is this site: http://lpetrich.org/Science/GeometryDemo/GeometryDemo_GMap.html. It has a couple problems, though: 1. There is no easy to ...
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Add Points shp attributes to Polygon shp by Point location (as Spatial Join in ArcGIS)

I have a set of points in .shp (ESRI, available here: http://ulozto.cz/xGqRVFrR/voronoi-zip). I would like to calculate Voronoi tesselation from the points, thus create polygons. So far, so good. ...
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Cross validation in thiessen polygons interpolation

I apply Thiessen Polygons interpolation using the krige command in the gstat R package. Using krige without a variogram model sets automatically krige function to perform IDW, and when nmax parameter ...
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Does fixed classes exist in QGIS?

I'd like to create several images of voronois polygons in QGIS; each images having differents values joined to the voronois. I tried to load a qml style with the values I want to keep (8 classes : 0>...
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Is there any way to set a processing extent for QGIS:Voronoipolygon?

I was playing around with the QGIS:voronoipolygons command line function from QGIS and noticed that there was no option for setting the processing extent. This causes QGIS to pick the minimum extent i....
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Fill larger polygon empty space with closest subset of polygons

Looking for an ArcGIS or QGIS solution. I need to divide up the space of the large single green polygon. Each new polygon would represent "nearness" to the purple polygons and have the ID of the ...
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1answer
619 views

Smoothly interpolating Polygons from set of coordinates?

I'm still quite new to QGIS and I'm using it to display and analyze my soil data. I have point information on the distribution of the soils in a specific area and I need to create a soil map from that....
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Polygon of Voronoi cell using scipy.spatial?

I have points (e.g., lat, lon pairs of cell tower locations) and I need to get the polygon of the Voronoi cells they form. from scipy.spatial import Voronoi tower = [[ 24.686 , 46.7081], [ ...
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Thiessen Polygon Total Area Calculations Model Builder/Python Code

I am attempting to create a tool using Model Builder (and Python code) for calculating the average annual precipitation of a study area using the Thiessen Polygon Method. My model runs good other than ...
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Thiessen Ploygon Bifurcated Areas Calculations

I have a SewerGEMS network of a sewerage scheme for a town. The town is divided into 17 wards having different population densities in (Population/Hectare). There is an AutoCAD drawing showing the ...
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Calculations of Thiessen Polygon Bifurcated Areas

I have got a SewerGEMS network of a Sewerage Scheme for a Town. The Town is divided into 17 Wards having different Population Densities in (Population/Hectare). There is a AutoCAD drawing showing the ...
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131 views

What is the correct cartographic projection to calculate a Voronoi tesselation?

I have a set of points with known geographic coordinates. I would like to compute a Voronoi tesselation from these points in order to obtain areas of influence. The geometrical area of each Voronoi ...
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1answer
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Thiessen polygons of sub-districts to lie within district boundaries [duplicate]

I'm using ArcGIS 10.1 and am fairly new to it. I have the latitude and longitude of sub-districts, and wish to create Thiessen polygons of these sub-districts. I also have shapefiles for districts (...
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Creating Thiessen polygons gives ArcGIS ERROR 000537 error in converting points to Voronoi Polygons?

I have a problem with creating Thiessen polygons for a set of points. I am creating them with Create Thiessen Polygons tool in ArcGIS 10.1). I am able to create them in a few steps (for parts of the ...
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Iterative point feature removal based on Thiessen polygon values

The background is: I have point feature class and Thiessen polygons created based on it. I wanted to know for each point Thiessen polygon area value, so I have calculated Thiessen polygon area value ...
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1answer
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Python Script that calls the Voronoi Polygons Function?

I've been looking to see if there was a way to call Voronoi Polygons function found in Vector/Geometry Tools, directly from the code but I have not found one. Does this currently exist? Is there a way ...
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636 views

Get Coordinates of Voronoi Polygon Vertices [duplicate]

Is there any chance to get the exact coordinatas of the voronoi polygons? I am using Qgis software and I have the "center" (redpoint) of the polygons and I would like to export the polygons corners ...
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Graduated colouring Voronoi polygons? (QGis)

I've got a huge database of depth points for the whole Irish sea which I'd like to be a nice smooth surface, or at least have a depth value associated with the entire area (i.e. include the inter-...
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1answer
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Offsetting Points by location

Sorry If you've read this before - I've tried to change the content so that it reflects what I need a little better. This question was marked as a duplicate although I read the the answer to the other ...
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Create Voronoi/Thiessen polygons in QGIS around 3 points

Running QGIS 1.8.0 I have three bus compounds. I would like to generate Voronoi/Thiessen polygons around those three points. Following Voronoi/Thiessen adding an all school points will allow us to ...
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1answer
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How to find nearest neighbors of polylines?

I have a shapefile containing irregularly placed polylines (i.e., survey routes). Following the general idea of a paper I read, I would like to use tessellation to identify the neighbors for each ...
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1answer
837 views

How to grid unevenly sampled categorical data?

I am looking for a method for gridding categorical data. I have extracted from nautical charts and field sheets a collection of points specifying the nature of the surface of the bottom of the ocean. ...
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Is there a described GIS method for creating catchment areas based on nearest driving distance?

ie. a combination of Voronoi polygons with isochrones, so that the Voronoi polygons are based on driving distance instead of Euclidean distance. Is there a name or a described method for this?

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