Topology describes non-metric relationships among geometric figures, such as adjacency, containment, and orientation. It is a branch of Mathematics, which deals in geometry without measurement.

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How to solve “features were not reachable” warning message using v.net.distance in GRASS

I'm using GRASS 7.0.4 under Linuxmint 17.1 KDE. I need to build a raster with the shortest distance from every pixel to a city following a road. I have two shape files, the city (point) and the road ...
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42 views

Editing with Map Topology performance in ArcGIS Pro?

I have been working on some basic cartography for a fantasy world I am creating, and ArcMap 10.4 was being slow on editing some of the large island polygons I am creating. I figured that as all I am ...
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16 views

topologically valid features from google earth

I'm currently working on QGIS and ArcGIS software for creating land use/land cover and road network map from Google earth. I traced the shared boundary between two land-use types twice since i don't ...
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Gas Utility Routing software in open source or algorithm [closed]

objectives : To make a web application for gas utility that can perform upstream and downstream I have googled a lot but cannot find any Gas utility routing in open source. what i have is data for ...
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pgRouting problem: creating topology where segments touch

I am working my way through the example in the pgRouting manual (2.2). After running pgr_createTopology() and pgr_analyzeGraph(): pgr_test=# SELECT pgr_createTopology('edge_table',0.001); NOTICE: ...
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43 views

Problem with polygon topology in ArcMap 10.4

I want to find errors - overlapping polygons in ArcMap 10.4. I created topology for my polygon layer (buildings) but error inspector shows me that all of my buildings are errors which is of course not ...
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24 views

Get results for each topology errors for Polyline or Points? [closed]

When you set up a topology to build topology rules for each polyline, or points, is there a way to get the results or summary for each Line Errors? For example, when you set "Must Not Overlap", ...
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topology problem in the python script(arcpy)

I'm using Python 2.7 and ArcGIS 10.1. I have one topology problem in my Python script and I don't know how to fix it. I have one road and I want to select polygons with a query where intersect with my ...
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38 views

Two inner polygons touching and covered by two different outer polygons

I need to create a topology where 1 and 2 touch but don't overlap, a and b touch but don't overlap, and 1 covers a and 2 covers b. Is it possible to achieve this? I've tried various snapping ...
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pgRouting “Can't find Table”

I am using pgRouting version 2.1.0. I am using pgAdmin III. I have created a street network using Anita Graser's guide: https://anitagraser.com/2013/07/06/pgrouting-2-0-for-windows-quick-guide/ But ...
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31 views

not all OSM polygons downloading in QGIS

I have been trying to download all of the polygons contained within OSM for a particular extent of the city. When I do this through > Vector > OpenStreetMap > Download Data, however, many polygons ...
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29 views

qgis snaps to outside instead of boundary

I have polygon layers that I need to be covered by other polygon layers, and many of my inner layers have a vertex on the border of an outer layer or in some cases they share an edge. Both ST_Covers ...
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How tool to split polylines into two-part lines at vertices in ArcGIS for Desktop 10.1?

I'm using ArcGIS 10.1 SP1 at and we have a problem. There is a serious topology bug that I've mentioned in another question that is affecting our workflow. At present, Esri has stated the fix will be ...
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1answer
37 views

How do I export data points from topology checker into an attribute table?

I used topology checker in QGIS to find all dangles in my roads polyline shapefile. The topology checker returned about 528 dangling ends, also called errors. How do I save these points into an ...
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1answer
46 views

Generalizing (simplifying) polygon shapefile or feature class in ArcMap while preserving topology?

I came across How to generalize a polygon file and maintain topology in QGIS? which asks for a QGIS solution to my exact question. I'm trying to do this in ArcMap. I start with a polygon shapefile ...
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5answers
3k views

Generalizing polygon file while maintaining topology in QGIS?

I have a polygon Shapefile, which I need to generalize. How can I generalize the poligons and ensure that there are no topological errors like "slivers". I already tried: Vector -> Geometry Tools ...
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1answer
49 views

QGIS topo snapping not working

I am using QGIS 2.14.0 and I need to fix some topology errors. Problem is that when I move polygon node to the another node they seem to snap correctly. However, when I move that node again, in too ...
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24 views

How to ensure that line features are connected to other line features at a vertex

I have a dataset with many line features that are all connected to each other. I want to ensure that they are connected at a vertex on the other line and not just an edge. I figured out one way: Use ...
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37 views

Loading Topology Rules in ArcGIS for Desktop with Basic license

Recently I've read that it's impossible to create topology rules below Standard License Level, BUT that one can load and use those rules (created in Standard e.g.) on a Basic License. How exactly does ...
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460 views

How to interact with GRASS GIS vector map topology “level/layers” from terminal/command line?

Is there anybody out there that can maybe assist in the most simplest form of code to call on command line to "export topology" (which is level 2 information in GRASS) as separate spatial data, as ...
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1answer
57 views

Does QGIS have an autocomplete polygon option like the one in ArcGIS?

I am trying to do digitizing in QGIS, but I do not see an option that I have seen in ArcGIS - autocomplete polygon. I would like to make two adjacent polygons topologically correct, and can not find ...
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37 views

ogr2ogr (or other) simplification of polygons with shared boundaries

I am trying to simplify a collection of 100,000 or so polygons containing nearly 4 million vertices. The data is stored in a 2GB shapefile so there is no explicit representation of the topology ...
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modelbuilder, combining models, output dataset type

I am combining two models and for some reason the output dataset from first model is not being accepted as input in the second model. Here is the screenshot of the first model (just last part of it): ...
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2answers
302 views

Automatically apply topology rule to only selected portions of a .shp file?

I am looking for some examples/tutorials on how to apply a topology rule to only a selected portion of a shp file using a script in ArcGIS/GRASS. Using ArcGIS seems to always require an interactive ...
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137 views

Finding Topology Errors toolbox or extension?

I do not remember if I add this Topology Errors extension or toolbox to my ArcMap. I would like to know more about this toolbox. This is not the same as the Topology toolbox that comes with the ...
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1answer
83 views

ITopologicalOperator::Simplify not removing self-overlaps

I maintain an application whose main job it is to take esri-ish things from users and turn them into sql spatial objects in our database (2008 R2). Below is an excerpt that may be useful: public ...
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2answers
289 views

Snapping polygons while reshaping edges?

I have two Polygons, A and B, in two shapefiles. Is there any automatic way to reshape the edge of Polygon A according to the edge of Polygon B?
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33 views

How to run QGIS plugin from python script

I would like to access external QGIS plugins through a python script. I have been able to access the built in QGIS processing and vector toolbox, but have been unsuccessful with external plugins such ...
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58 views

Does QGIS support topological editing of lines?

Does QGIS support topological editing of shared vertices between two or more lines? When in editing mode, if I select a vertex at an intersection, it seems that sometimes it will move all lines ...
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229 views

Joining layers with respective elements with PostGIS Topology

I'm currently using PostGIS topology extension, but I have some difficulties in understanding how the structure works: One of the key points is the use of "layer"s: as of what I understand, features ...
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21 views

Remove inner border and extend dangles to outer border

I'm struggling with a massive file of grids that need borders extend or snapped onto the outer border of the file. I'm looking to batch this process as I'm currently using topology and and tracing ...
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How to use the TopoViewer in the QGIS DB Manager?

I'm just wondering what the TopoViewer in QGIS is doing. DB Manager (PostGIS) says 'Schema "schemaname" is not registered in topology.topology'. Unfortunately there is no help available and I can't ...
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2k views

Creating polygon of gaps/holes from several shapefiles using ArcGIS Desktop?

How can I create polygon of gaps/holes if I have several shapefiles. Do I really have to merge all layers, it it big amount of data (NEW YORK roadbed, buildings, water,parks etc) I have ET geowizards ...
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52 views

Administrative boundaries topology rules

I have administrative boundaries at 4 levels, each one is a feature class in a file geodatabse. Each level should be a split of the layer above. In other words one polygon from level 2 should be ...
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2answers
831 views

Topological relationship between two polygon feature layers in VBA and ArcObjects? [closed]

I have two polygon feature layers: one representing land parcels and one representing roads. Some land parcels (polygons) coincide with a part of a road (another polygon feature). How can I check ...
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1answer
64 views

Geodatabase topology and geometric network on the same data

I know that I can't have a topology and geometric network on the same data in the same dataset in ArcSDE. But is there any solution how to do this? I need geometric network for generating diagrams via ...
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TopoGeometry commands with postgres are really slow

After messing around quite a while, I was finally able to get a topogeometry converted from my geometry table following the example of toTopoGeom. I have the topology extension, with a topology schema ...
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1answer
55 views

Edit polygon borders in QGIS preserving topological correctness (planar partition)

Given a layer of polygons that is topologically perfect, i.e., has no overlaps or gaps between the polygons, is it possible to manually edit the edges of the polygons in QGIS in a way that preserves ...
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1answer
73 views

Checking if two WGS84 lines intersect in JavaScript

I am trying to work out given two GeoJSON lines (WGS84), if they intersect (i.e. cross one another). Let me give some pseudocode to illustrate: // Providing Line 1 = lon1, lat1 and Line 2 = lon2, ...
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1answer
635 views

JTS - Java Topology Suite - Calculate radius from a given point

From point A, I want to check if a point B is within a certain radius from A. How calculate it usindo JTS? I tried this: Coordinate posicaoAtual = new Coordinate(-12.974900375893823, ...
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1answer
706 views

Road Topology Problem solution for junction

I am working with a Road Network. I have digitized the lines with AutoCAD Map 3D. Then Imported it to ArcMap. After entering all kind of database I have created Routing Dataset. But unfortunately its ...
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Moving feature classes between FGDB's creates unknown topology errors [closed]

I am attempting to merge together multiple large feature classes from different FDGB's into a single feature class and am getting unknown topology errors when checking for gap and overlap rules. I ...
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1answer
5k views

How to convert lines to polygons using NetTopologySuite?

I am trying to convert lines to polygons using NetTopologySuite(a C# port of Java Topology Suite JTS). I ran the sample console code succesfully and it generated two polylines. I then tried to run ...
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1answer
2k views

Intersecting two polylines using ArcObjects?

I have two polylines and would like to find the intersection(s) using ArcObjects / VB.NET. I'm using the following code: Dim topoOp As ITopologicalOperator = TryCast(pTestPoly2, ...
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2answers
57 views

Using ArcMap Topology to make admin boundaries match up?

I have two separate datasets ('Wards' and 'Census Output Areas'), whose boundaries don't quite match up (see below - wards in red, COAs in grey). Is there a way of automatically adjusting the Ward ...
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2answers
166 views

Simplify/generalize Polygons and keep topology of different layers PostGIS/QGIS

i have some polygons of a country, states, districts, communities and i want to simplify the geometry. i already simplified the geometry of each layer but afterwards of course it doesnt fit with the ...
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Snapping leaves small gap between features in ArcGIS for Desktop?

I'm using classic snapping in ArcGIS 10.1. At the scale (1:5,000) that I'm using to snap the edge of one rectangular feature to the edge of another rectangular feature, snapping seems to work fine. ...
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1answer
1k views

Creating adjacency matrix of topology graph of ArcMap for shortest path using ArcObjects? [closed]

I have created a topology graph of a polygon feature and I want to find the individual FIDS of the lines of the polygon. I want to construct an adjacency matrix to create the shortest path. How can I ...
3
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1answer
178 views

How to remove spikes in Polygons with PostGIS

I'm trying to validate the topology of a shapefile. I managed to repair cases of overlap and gaps, but i can't resolve cases of spikes. The image shows one example of this situation. I used the ...