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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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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27 views

Topology in ArcMap [on hold]

When creating a topology layer...what are some common errors that occur for users?
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1answer
32 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
34 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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17 views

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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2answers
44 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
75 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 ...
3
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1answer
86 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 ...
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57 views

Create polygon from lines in PostGIS

I'm trying to divide a polygon in smaller polygons from a line, but I think I can't use the st_split function. What I need is to create small polygons inside a big one, using linestring grid. I've ...
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2answers
91 views

Tool or program to clean polygon dataset

I have a polygon dataset (shapefile, mapinfo tab file) which I would like to "clean" to be topologically correct. The polygons are assigned an ID which represents a specific class. For example ID 3 is ...
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1answer
30 views

pgrouting - topology creation with explicit node file

Learning pgrouting, I would like to build a simple public transport routing engine. Starting with a simple metro network (DC in my case, see excerpt below), I would like to combine the line ...
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75 views

How to avoid topology errors when digitizing a road network?

I am working on a road layer project. For the snapping option I'm using the mode to vertex and segment and tolerance 5 pixels. When zooming in (to the max) I do not notice a gap. But when I use the ...
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37 views

Problem for Map Topology creation in ArcMap

I will create a map topology in ArcMap. My code defines the layer in my map topology but after call EditTopology Tools, a message show "No topology .... bla bla bla.." Any ideas why this would be ...
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1answer
48 views

Styles for Vector layers on QGIS

I'm trying to do some habitat suitability modelling on QGIS. I've downloaded several vector maps from Ordinance Survey (OS). So far I've found a Cartographic stylesheet for "OS VectorMap Local". This ...
6
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1answer
83 views

Automatic creation of polygons from Feature Class points in ArcGIS for Desktop?

I have two point feature classes, let's call them A and B. They are well-spaced and the points are non-overlapping: My objective is to create a topology using these two sets of points by connecting ...
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1answer
62 views

Arc-node topology data structures in Python GIS packages

I am looking at using the traditional arc-node topological data structure to make some spatial data analysis more efficient. I would like to avoid reinventing the wheel. Is there an implementation in ...
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1answer
115 views

QGIS Topology Checker Wrong

I use topology checker and add a rule that polylines must not have dangles. It find errors for all 36 polylines but I think some topologies are correct at the right side. Can you help me how can I fix ...
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36 views

How to check if a point is snapped to a line in QGIS

I have two vector classes, sg_point and sg_line. Any sg_point HAS to be snapped to a sg_line. I should not find errors if I use snapping correctly, but in case there are errors how do I check in QGIS? ...
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2answers
185 views

What is nontopological geometry?

I need a simple understanding of nontopological geometry. I am completely new in this area so please correct me if I am wrong. As far as I understand in topological geometry the object(say a line) ...
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34 views

ArcGIS: Is there any way to use topology on data in different feature datasets?

I am using ArcGIS 10.2 desktop on an SDE/versioned environment. We use the ESRI local government information model, except that we do not use parcel fabric. I am responsible for maintaining several ...
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1answer
212 views

How to test for 'if arcpy.exists' with RemoveFeatureClassFromTopology stand-alone script?

I have some datset topologies that i want to loop through, but I need to test for the assignment of feature classes so the scripts dont fail. (Using Win 7, ArcGIS 10.2, Python 2.7.5 and a file GDB) ...
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2answers
206 views

How can I remove the gap between two polygon boundaries in QGIS?

I have a couple of messy polygon boundaries (example data) that should share a boundary but don't: I've had a look at some suggested tools for a similar issue using ArcGIS in a separate question ...
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1answer
19 views

Territories that are not connected

I am looking for territories that are divided between two or more countries in a non-contiguous way. E.g, country A receives the western part of the territory, then country B receives a part to its ...
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85 views

Problems using GRASS tools for topology validation in QGIS

I'm working with a shapefile of Enumeration Districts (Setores Censitários) of the 2010 Brazilian Census. Enumeration Districts (ED) are smallest areas for which Brazilian Census data is available. ...
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121 views

How to add rule and add feature class to topology using arcpy and stop getting error 000732?

This script successfully added feature classes to topology when that is all I had scripted it to do. Now I've added the add rule parts (#added) and it's still just adding feature classes without ...
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1answer
71 views

Orphan road segments

I am working with OSM road data for a developing nation. Included in the dataset are various small networks of roads that are orphans or islands i.e. not connected to the main road network. For ...
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1answer
166 views

What's difference between Topology and Check Validity in QGIS?

I would like to know what the difference is between the Topology Checker and Check Validity tools? Is there anyone who knows of a good document or tutorial that explains functions of these tools? ...
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104 views

Topological errors after dissolve - how to avoid/get rid of?

After dissolving a layer in QGIS 2.8, I get a lot of topological errors in the new (dissolved) layer. Any suggestions as to how to get rid of these errors without manually editing each one? ...
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49 views

how to create Topology table?

i have gis database called Madar in pgadmin with postgis and pgrouting extension, all the data inside gis database already inserted by shp2postgre tool , what i really need now is how to make topology ...
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1answer
113 views

How to correct topology area boundary errors (slivers/gaps) on arcs in arcgis / arcsde

I use arcgis 10.1 (arcinfo licence) with arcsde to connect to a SQL Server database. The initial dataset has around 100k polygons (used for land registration, having a resolution that is around 1cm ...
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166 views

Removing pseudo-nodes using QGIS Sextante plugin?

I have a road network (vector) that i'm interested in carrying out some space syntax analysis on. Predictably my GIS data is in a pretty terrible state. For example, there are a bunch of roads on the ...
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1answer
118 views

Enabling: Raster and Topology

I'm new to GIS and tile servers. I've installed TinyOWS pretty successfully except for what looks like to be some dependency issues. I have installed PostGIS and also PostgreSQL. PostGIS is supposed ...
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2answers
102 views

QGIS Editing: move - both - nodes after Cut has been performed

I just ran into unexpected behavior while editing a polygon shapefile in QGIS 2.8.2. Scenario: A polygon: Then I cut that polygon into two seperate poygons: Then I use the Node Tool to move a ...
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1answer
60 views

PostGIS Topology Requires Admin

I am running PostGIS on an Ubuntu server. I am able to add the Topology extension via CREATE EXTENSION, but when I try to use it as anything other than an admin I am denied permission. I ran GRANT ...
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1answer
31 views

Double Entries/ Errors with Digitizing Polygons

I have a layer that has errors, i mean polygons have double entries (digitized twice), i can edit manually but there's a lot of attributes and it will take ages to clean the data. Is there any short ...
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1answer
127 views

Parsing path and calculate value in model builder

I am experiencing an issue with the model only tool calculate value. I am attempting to use the parse path and calculate value model only tools to force a feature dataset into the create topology ...
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1answer
81 views

start editing encountered one or more layers with error and can not continue this data is not editable

I create two feature classes by importing an already existing layers then I create a topology and I set the rule such that a point feature class must be covered by endpoints of the other line feature ...
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160 views

Invalid Topology/Topoengine error: Intersect and Clip

I have a large, provincial extent gdb file with numerous detailed polygons (representing roads, buildings, forest cover, etc), and want to clip this layer to about 700 unique polygons, some of which ...
0
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1answer
83 views

Delete Features from a feature class that participates in a topology

I have an enterprise geodatabase and I would like to delete features using the tool from a feature class that resides in one of the feature datasets and participates in a topology. I tried using the ...
2
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1answer
204 views

Enforce topology rule over a shapefile

I have a couple of shapefiles, the first one is a set of points, while the second one is a set of lines. I need to regularize the shapefiles in order to be able to generate a graph (adjacency list / ...
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1answer
56 views

TopologyException error during fortify SpatialPolygonsDataFrame

I tried to reproduce a recent question on spatial data visualization using ggplot2 and received the following error message during fortify(world, region = "ISO3"): Error: TopologyException: Input ...
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46 views

QGIS topology overlap check

I have checked topology rule must not overlap with and i get error The problem is that i have check this many times, and made hole vertex after vertex so it is not possible that these objects ...
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68 views

Topology in Arcgis and QGIS

I have been studying topological methods like 4 intersection , 9 intersection, dimension extended and CBM (calculus based methods) like RCC-8. I want to know which of this method is used for ...
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1answer
40 views

Setting junction properties in ArcGIS Desktop?

I have a situation where I have a line feature class and need to build a network out of it. The lines represent roads. I wonder how I can model the intersections on the network. Almost all of them ...
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50 views

How to identify Topology Exception

Anyone have any innovative way(s) of "quickly" marking topology exceptions. I have ~300,000 bridges which have pseudo nodes located on either side of the bridges where the bridge and road endnotes ...
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0answers
347 views

Grass Processing tools via QGIS : v.clean snap, chdangle, and rmdangle

Using QGIS 2.6 Grass Processing tools, I'm trying to clean up topology on a water network layer. I noticed topological errors when first trying to break all lines on intersections using v.clean break. ...
6
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2answers
107 views

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
139 views

Geometric Network Build Error

I'm trying to create a geometric network of pipes, sewer structures (points) and manholes (points) inside a of an SDE. I can create the network in a file geodatabase but when I try creating it inside ...
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2answers
179 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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1answer
50 views

Select and count street pattern features (morphology) using ArcGIS for Desktop?

I'd like to be able to select and count the number of cul-de-sacs, lollipops, dead ends, or other types of street structure in a hillside community.