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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Automatically add vertex to polygon where vertex of another polygon touches it?

The polygons that I use in ArcMap 10.2 are drawn so that they snap to each other, but never overlap. I've described a general case in the following image: A polygon is defined by the minimum ...
2
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1answer
87 views

How to suppress polygon boundaries shared by objects of same type in QGIS?

Given polygons - like landcover in OpenStreetMap or street areas in cadastre - how can one suppress those polygon boundaries which are shared by objects (features) of same type in QGIS (see figure ...
1
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0answers
58 views

ArcGIS planarize vs autofixing “must not intersect or touch interior” topology

trying to fix topology errors in OSM here. I am wondering whether ArcGIS planarize is essentially the same as creating a topology that says a class must not intersect or touch interior. Then ...
2
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3answers
473 views

X,Y Tolerance vs. Cluster Tolerance

I can set a "X,Y tolerance" or use default when I create a new feature class. I can set a "X,Y tolerance" or use default when I create a new feature dataset. I can set a "Cluster tolerance" or use ...
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1answer
65 views

Simplifying polygons in ArcGIS considering contains-one-point topology rule?

I want to simplify polygons using the "Simplify Polygon (Cartography)" tool in ArcGIS 10.2. Additionaly there is one point in each polygon and this condition should still be fulfilled after ...
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1answer
66 views

Is there any topology handler in QGIS?

When importing autocad maps, sometimes topology will be chaos, this need to be amended. And when I add new topology in QGIS, how to save that to the postgreSQL? Is these functions included in QGIS or ...
3
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1answer
166 views

How do I save topology errors in QGIS?

I'm currently doing a project on finding blocked roads in a road network layer. I've figured that I can use the topology checker with the rule 'must not have dangles' and find them this way. But I ...
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0answers
74 views

Metric maps vs topological maps for path finding and UI rendering of indoor floor layouts

I'm building a software to map indoor floor plans of large facilities (like malls). I read through some of the questions on this forum, but my constraints are a little different than the ones ...
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0answers
74 views

Polygon Layer Cleaning with QGIS

I have a little situation with my data. I have vectorized a raster layer, and now I have some issues with the geometries, as you can see in the picture. Most of errors I have are like this one. ...
3
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1answer
100 views

How to connect lines with gaps to continuous line?

and I have a lot of this problem like in image. The two line are separated but i want a continuous line. What rule should I choose in Topology Checker? I want to know all the separated line, so i can ...
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1answer
139 views

Polygon intersection with LineString in PostGis

I have a table which contains GPS coordinates at certain times. I created a LINESTRING from them ordered from the oldest to newest. I also have a POLYGON and I would like to determine the subset of ...
3
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2answers
309 views

Getting line FID from polygon ITopologyGraph

I want to export polygon Arc list to txt file for that I created topologygraph for personal geodatabase feature class (polygon) using ITopologyGraph::build. I got polygon FIDs but I am not getting ...
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2answers
48 views

Splitting polgons in QGIS produces topology errors

I am trying to split existing polygons but when I do, gaps and overlaps are created between the polygon I am cutting and adjacent polygons. I have snapping switched on and have enabled topological ...
2
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2answers
724 views

Why does Erase give ERROR 999999 (Error executing function Invalid Topology Negative point valence)?

I am getting the following error when I try to erase a set of data from a file within a gdb. Any idea on what to do? I have done repair geometry multiple times on the input/erase datasets. I have 16GB ...
2
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1answer
79 views

Editing polygons simultaneously in ArcMap?

I have two polygons: How can I reshape both Polygon 1 and Polygon 2 at the same time? Will the area of each polygon change automatically in the table after reshaping? I'm using ArcMap 10.1.
2
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1answer
64 views

Topology Editing using ArcView (now called Basic) license level of ArcGIS Desktop?

I am building a geodatabase from data collected on a GPS handheld in the field. The GPS device collects decently accurate information but I need to make sure all the polygons, lines, and points are ...
2
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1answer
3k 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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8answers
2k views

How to build topology without Standard/ArcEditor or Advanced/ArcInfo license?

I have a huge dataset that I am capturing that was full of errors previously and I want to make sure that the new version is error free - which can be very time consuming with only a Basic/ArcView ...
7
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3answers
2k views

Create features from ArcGIS Topology errors

I have imported field users shapefiles into an ESRI geodatabase so that I can create some topology rulesets that identifies the errors as needed. Unfortunately the field users do not have a license ...
4
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2answers
468 views

Topology Edit Tool in ArcGIS Engine

Is a Topology Edit Tool available "out of the box" for ArcGIS Engine 10? Or do I have to write one myself?
5
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2answers
375 views

Just view topology errors in ArcGIS

I have a basemap (parcels), which is to be used as target for several conflation tasks. This basemap MUST NOT be modified in any way. The basemap ist part of numerous topology rules. Each time ...
2
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2answers
179 views

What is the difference between Intersect & Overlap in ArcGIS Server?

When you run a Query Task on the ArcGIS Server's REST Endpoint, you need to give a spatialRel There are two spatial relationships which are quite similar: esriSpatialRelIntersects & ...
2
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1answer
590 views

What am I doing wrong with QGIS v.clean?

I thought I understood how the GRASS v.clean tool worked in QGIS (in 2.6.1 Brighton) but I keep getting unexpected results and errors with a polygon ShapeFile. I've run the QGIS TopologyChecker with ...
7
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1answer
487 views

Algorithm to fill the gaps adjacent to parcels

I would like to find a way to fill the gaps between the road and its surrounding parcels, like described in picture below: I have different parcels like A and B , i want to fill the gaps by adding ...
8
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1answer
188 views

Suitable algorithms for simplifying isochrone polygons

I'm looking for an algorithm for simplifying isochrones which were generated using OSM data. These are generally characterised as having lots of small "holes" mostly due to missing OSM data but also ...
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5answers
2k views

How to generalize a polygon file and maintain 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 ...
3
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0answers
71 views

How to simplify polygon shapefile and maintain topology? [duplicate]

I'm looking for a straightforward answer that actually works...not a 'duplicate question' flag. None of the other solutions posted in similar threads actually work...they all have dead-end answers ...
2
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1answer
104 views

ArcMap remove feature-class from feature-dataset

I am using ArcMap 10.0 (Editor). I have got a feature-dataset within a GDB with several feature-classes and an topology. I am unable to find a way to delete/remove a feature class from that ...
0
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0answers
75 views

Any way to speed up my postgis topology creation?

I need to do topology aware simplification, and I'm investigating PostGIS's new topology extension. However it's taking a very long time to create the topology, and I'd like to know if there's ...
0
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0answers
45 views

How to eliminate sliver polygons with QGIS [duplicate]

I need to remove sliver polygons within a shape, but using QGIS 2.6 generates some failures to the process. I mean the program freezes or shuts down and I don't know why. Maybe there's a bug or it ...
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0answers
96 views

QGIS Topology checker wrong results?

I am trying to understand topology checker results and frankly i dont get it - probably i am doing something wrong. Source - Point layer Target - Polygon layer Must be inside - that is working as ...
1
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1answer
73 views

Grass GIS “v.in.ogr”: How to prevent crossing lines from beeing split where they don't share a common node?

I want to import a road network into grass gis to run network analyses. I use "v.in.ogr" to import my road shapefile. The problem is that Grass GIS seems to split every crossing line no matter if they ...
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0answers
603 views

Intersection postgis TopologyException

I'm trying to make a quite simple analysis in Postgis, but I'm finding some problems. I want to in the first place create buffers for then, intersects themselves but one, this will be differenced. ...
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0answers
34 views

GRASS: How to remove several categories from a geometry?

I am totally new to GRASS (and have found it difficult to get into that way of thinking and its terminology). I use grass70 under Ubuntu 14.04. I have the following problem which I have tried to ...
3
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1answer
133 views

Gaps and overlaps appear after cutting a previously topologically clean shapefile?

I'm using QGIS 2.2 and I have a polygon shapefile which was created by someone else. I have managed to get the shapefile to a topologically clean state by running v.clean but when I tried to cut the ...
11
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4answers
1k views

Efficiently finding the 1st order neighbors of 200k polygons

For every one of the 208,781 Census block groups, I'd like to retrieve the FIPS IDs of all of its 1st order neighbors. I have all the TIGER boundaries downloaded and merged into a single 1GB ...
3
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1answer
185 views

QGIS Topology Checker select errors

I have used the Topology Checker plugin in QGIS to create rules to identify errors in my layer. For example, I have used it to search for all overlapping polygons. This plugin is great for finding ...
1
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1answer
833 views

QGIS - Identify overlapping polygons in single layer

I have a shapefile of buffered points in QGIS. I need to display all buffer polygons in this layer which overlap. I have experimented with the intersect tool, but this only seems to work if I am ...
2
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1answer
73 views

Is there a a way to add a topology dataset to an mxd with arcpy?

I have a script that identifies certain layers from a folder containing several geodatabases. Part of the scripts purposes, or intended purpose is to have it add a topology dataset to the dataframe. ...
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1answer
39 views

How to find points present in one layer but not in a second layer, using ArcGIS?

I have two layers, A and B, with B consisting of a proper subset of the points in A. How can I produce a third layer, C, consisting of just those points found in A but not in B. In R, I would just ...
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1answer
110 views

OSM Data 'gid' column

Eventually I came to know that in order to use pgr_createTopology function to create topology network on my imported OSM data (using pg_routing and postgis on postgresql), apart from the_geom geometry ...
2
votes
2answers
103 views

vb.net arcobjects determine whether arcmap is in editing session

I have a vb.net arcmap addin which provide a function to validate geodb topology. But there is a problem, when I am not in editing session and use the function, arcmap will crash. In this case I ...
2
votes
0answers
318 views

Remove pseudo nodes in QGIS

I have a shapefile of city streets. I tried to run the Road Graph tool on them but the select box does not populate with the layer. I ran the Topology Checker on the layer and found that there are ...
2
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1answer
2k views

How to populate From Node and To Node fields for a polyline feature class? (ArcGIS 10)

I need to populate FNODE and TNODE fields for my roads dataset. I have an intersections point feature class that has unique ids, and I need each road segment to have an FNODE and TNODE value that ...
1
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0answers
78 views

vb.net arcobjects validate topology function only works after I use arcmap topology tool validate topology first

I find a strange thing occasionally, I have a validate topology function developed by vb.net arcobjects. It work not properly. The case is: open arcmap start editing use my validate topology ...
0
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1answer
49 views

vb.net arcobjects check if topology has error

I follow the esri example for validating topology, is it possible to tell whether topology error exists? The code I use: ' Step 1 - access a topology Dim topoUiD As UID = New UIDClass ...
0
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1answer
98 views

arcsde topology register issue

I am in trouble with the topology in a sde database. I create a topology in a dataset from arccatalog, after managing to register it as aversion, I try to validate it from arccatalog, it tells me ...
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0answers
30 views

How can I associate a consistent polygon area with a set of attributes using a topology?

Consider the following topology. SELECT CreateTopology('topotestschema', 0, 0.01); CREATE TABLE topotest (id SERIAL PRIMARY KEY, data TEXT); SELECT AddTopoGeometryColumn('topotestschema', 'public', ...
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1answer
52 views

Using topology to connect nodes <100m apart only

I have a bunch of line segments, most of which have gaps that are 100m or less. What I'm trying to do is connect these gaps so I have a series of connected line segments BUT leave nodes that are over ...
1
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1answer
62 views

Working with topology errors sample code error

I am following the sample code from ESRI for checking topology errors using vb.net. But in my workspace an error happened. My code is listed below: ' Step 1 - access a topology Dim topoUiD As ...