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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286 views

How to add topology to PostGIS 2.0?

I have installed PostGIS 2.0 and need new topology but it doesn't seem installed by default. I found a lot of command line to install postgis 2.0 with topology but is there a way just to add topology? ...
4
votes
2answers
721 views

How can I identify gaps in polylines and polylines with more than one end point using ArcGIS 10?

I have a multipart polyline shapefile containing a large number of lines, some of which are broken by gaps and some of which have more than one start and end (by mistake - see attached). I need to ...
5
votes
2answers
728 views

How to solve “Cannot create topology” in ArcCatalog?

I have a FileGeodatabase in ArcGIS 10.0 with a feature dataset and five feature classes (3 polygon shapes, 1 line shape, 1 point shape). I'm trying to create a topology to verify some vectors. ...
5
votes
1answer
810 views

How to create adjacency matrix of topology graph of arc map for shortest path?

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 ...
10
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2answers
546 views

How do I describe a special relationship between connected edges?

Consider this simple situation where three edges connect at a node: I’d like to write a succinct and clear description of the relationship between A and B in such a way that differentiates it from ...
3
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2answers
561 views

How to find self-intersecting polylines using ArcObjects?

If I have a polyline, how do I figure out whether it is self-intersecting? I tried to use ITopologicalOperator.IsSimple Property, but it always returns true. Are there any ways of doing these kind ...
3
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0answers
71 views

Topology validate error

Im using Arcmap 10.1 version.I don't know where i made mistake my database. I have attached an example image to show the Error Report.
2
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1answer
93 views

How can i identify this error? Must not connect point more than one line feature

I have attached an example image to show the problem: This is electrical network data sigle service point to connect more than one Service pole. Is it available any topology rules? I would like some ...
4
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1answer
223 views

Splitting polygons leaves null values

I'm trying to split polygons with overlaping line features, using Split Polygons tool from Topology toolbar. The problem I encounter is that only one from new polygons have old attributes and others ...
1
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1answer
35 views

Line FeatureClass shouldn't overlap with Polygone FeatureClass

Is there a way to setup such a rule in ArcMap 10 Topology that Line FeatureClass Features shouldn't overlap with Polygone FeatureClass Features?
2
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0answers
227 views

Snapping line endpoints to a point feature class by adding a vertex

I have a line feature class whose endpoints should snap to the closest point in a points feature class. The problem is, I do not want the lines to move, but rather a vertex must be added to the ...
8
votes
2answers
527 views

How to speed up space partitioning in postgis?

I've a bunch of overlapping polygons and I'm trying to partition the space to avoid having overlapping ones. I think my problem is fairly simple. Using some ESRI product and ...
2
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1answer
118 views

Compiling a list of units that border each other

I have a shapefile of U.S. counties. I am interested in compiling a list of those that border each other. In particular, I am interested in those that border each other but are in different states. ...
5
votes
1answer
711 views

How you can repair invalid topology errors within postgis?

I've imported the shapefile of corine land cover project to my postgis database and the select gid, ST_IsValidReason(geom) from gis.clc2000 where not ST_IsValid(geom); returns in every occasion ...
4
votes
2answers
3k views

How to repair topology of a shapefile?

I performed an object-based image analysis using ENVI EX, and each of the classified features were exported as a shapefile. I transferred those shapefiles into ArcMap 10, and tried to intersect them ...
2
votes
1answer
61 views

how to judge the side from a point to a linestring

I'm working with NTS (NetTopologySuite), I get point geometry and a directed linestring, how to judge the side of the point locate with the linestring? one the left side, right side, or just on the ...
3
votes
2answers
290 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 ...
4
votes
2answers
948 views

Snapping two polygons together

I have a problem with two vector layers, both polygons. I have been digitising an historical map which contains large areas called townlands, filled by smaller areas called fields. I digitised both as ...
6
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1answer
342 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 ...
6
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1answer
755 views

FME - Can I write back into my original file geodatabase

I have a gas pipeline network which I have stored in an File Geodatabase as polylines. I've created an FME workspace to split the pipelines at fittings (valves, reducers, tees, etc) which are stored ...
2
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4answers
1k views

How can I create polygon of gaps/holes if I have several shapefiles

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 ...
7
votes
1answer
194 views

Optimize GEOSGeometry's spatial operations by avoiding thread-safety checks

A ranking algorithm I'm developing for a Django webapp requires performing spatial operations (within, intersections, sym_difference, etc.) using a query against large number of geometry objects. ...
17
votes
1answer
1k views

What's the status of Postgis 2.0 topology support in QGIS?

Having followed the Postgis developments over the past 6 months I have noticed a bunch of features which seem to be incredibly cool especially in the area of topologies and associating calculations on ...
1
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1answer
129 views

I need help to find out more information about Topology Errors toolbox or Extension?

I need someone out there who can answer my question. I do not remember if I add this Topology Editor Extension or toolbox to my ArcMap. I would like to know more about this toolbox. Thanks. (Changed ...
6
votes
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 ...
2
votes
1answer
1k 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 ...
2
votes
1answer
2k 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 ...
0
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1answer
2k views

How to resolve an Invalid Topology [Incomplete void poly] error from a geoprocessing service?

I am consuming a geoprocessing service from my Flex application. My geoprocessing service takes the input geometry, and intersects another layer. It then runs a Summery stats on the intersection ...
2
votes
1answer
583 views

How do I subdivide and edit polygons preserving topology?

I'm using QGIS. I have a layer made up of many adjacent polygons - let's call them "countries". I currently use the Atlas plugin to export each "country" polygon to a .png file. I want to further ...
4
votes
3answers
875 views

Questions on smooth lines on soil polygon?

In a couple of weeks I am going to do QA/QC on soil polygons and I'm wonder if there is a way for me to run a script or a tool box that allow me to find the jagged lines ? Alternative, my plan would ...
1
vote
2answers
283 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 ...
1
vote
1answer
3k views

Remove Holes Existing Within a Single Polygon in ArcGIS 10

I have a shapefile that consists of a single polygon. I have gaps within the polygon that need to be eliminated. The resultant dataset shoulde be a single, solid polygon. I have tried implementing ...
10
votes
3answers
955 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
votes
1answer
1k views

Intersect 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, ...
4
votes
0answers
231 views

Topology - To be, or not to be, that is the question [closed]

Topology, I mean "real" topology, is not a new concept and it's available since a long time in GRASS gis. I won't speculate the reasons myself but, after a long period of spaghetti model ...
7
votes
1answer
2k views

Ring Self-Intersections in PostGIS

This is a follow on from previous question. You will see I am a new PostGIS user. I have looked at the validity of the topology in my data and find around 1700 topology issues in the landcover ...
13
votes
1answer
956 views

Identifying topological relationships using PostGIS

I'm trying to perform a basic typology analysis using PostGIS. My objective is to find any polygons that touch other polygons. To do this, I thought the ST_GetFaceEdges would work (reference). I want ...
3
votes
2answers
411 views

Determine point relation to given line

In ArcGIS engine I have a polyline with From and To points. I also have a Point. How can I determine if the point is located on the right or left of the line on the plane considering the direction of ...
5
votes
2answers
325 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 ...
6
votes
2answers
714 views

What does 'building topology' mean for pgRouting?

From a couple of answers at gis.stackexchange.com and at the pgRouting mailing list I have found out that pgRouting 'builds topology'. What does that mean? If for example we import an .osm file into ...
2
votes
2answers
608 views

Topological relationship between two polygon feature layers

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 ...
6
votes
1answer
95 views

Dividing the world space to geographic sub-space

I am trying to divide the world space to geographic sub-space from "general" to "specific" locations and without using latitude and longitude information. That is, I am trying to think about the world ...
1
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2answers
979 views

Arc node topology in ArcMap

I would like to implement an arc node topology in arcmap. Do you know how can i build node topology from line layer in ArcMap 9.3.1?
2
votes
1answer
644 views

3d polylines and polygons

Is there a way to extract z values from a DEM into a polyline and/or polygon featurclass in arcmap 10? I would like to have 3d polylines and polygons to make cross sections in a CAD, but currently I ...
1
vote
2answers
327 views

topology of geometries in gis

http://imm.io/2cpJ What is the thinking of OGC to keep this point that "point have no boundry , it just has interior"... what do they mean? this notation: F**F*****...still i am confused due to OGC ...
18
votes
2answers
2k views

What are the benefits of Multipart Features?

Multipart points, lines, and polygons are implemented in nearly every GIS, but what benefits, if any, do they provide? In a relational database attributes shared by different features can be stored ...
12
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4answers
3k views

Remove Duplicate Polygons Using Open Source Tools

I have a shapefile containing features with duplicate geometries, but different attributes (e.g. a polygon with attribute XX, and an identical polygon with attribute XY). I want to identify the ...
9
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5answers
1k views

How to convert line simple features to topological network?

using Gdal/ OGR is there a way to convert a shp, kml, or PostGIS line layer into a network of nodes and segments so it can be used in packages such as networkx?