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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Analyzing differences between two shapefiles to put results into new shapefile?

I have two polygon shapefiles of the same region from two different years (1985 and 1997) and I need to analyse the differences between the two shapefiles resulting in a third polygon shapefile ...
0
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3answers
2k views

How can I easily detect gaps in a polyline using arcmap 10.0 (arcview license)?

I'm making routes by selecting links from a streets layer which I export as a new temporarely layer in arcmap 10. This layer which I call route_temp unfortunately can be very long and contain gaps, ...
3
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1answer
116 views

Learning resources for beginning differential topology for a programmer? [closed]

With this question I'm looking for suggestions about how and where to start learning differential topology starting from a good base of linear algebra and geometry, also consider that this know-how is ...
4
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1answer
734 views

Simplification algorithms for 3D topology

My problem is about simplifying a given topology that can be opened ( an usual 3D reconstruction of a given square on a map ), totally closed (like a perfect sphere) or a topology with holes ( a ...
5
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4answers
843 views

How can I create polygons of the area surrounded by roads / lines?

I'm currently trying to create polygons that represent the areas surrounded by roads. The roads are stored in PostGIS as points / lines so I have flexibility over what I can do with them. I'm ...
2
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2answers
1k views

Dissolve polygons - group to others with touching corners

I am working with some data that shows land management. There are many places where corners "touch". I would like to dissolve my dataset so that features are grouped (dissolved) with those that they ...
9
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1answer
383 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? ...
1
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0answers
549 views

How to handle/ avoid intersect errors when clipping the difference between two layers?

Using QGIS + Grass, I've added a shapefile of coastline and islands to my map. I then buffer this shapefile to create a coastal zone of a known width. At this stage the buffer consists of the ...
2
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1answer
1k views

File Geodatabase XY Resolution and XY Tolerance

Here - http://gisintelligence.wordpress.com/2011/04/19/limiting-xyz-geometry-drift/ I found the description of XY Resolution and XY Tolerance in "Arcgis World". I have a question - my cadastral data ...
4
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2answers
1k 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
2k 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
739 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 ...
4
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2answers
1k 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 ...
2
votes
0answers
92 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
143 views

Identifying “Must not connect point more than one line feature” errors in electrical network?

I have attached an example image to show the problem: This is electrical network data single service point to connect more than one Service pole. Is it available any topology rules? I would like some ...
4
votes
1answer
357 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
vote
1answer
84 views

Implementing topology rule Line Feature Class should not overlap with Polygon Feature Class in ArcGIS Desktop?

Is there a way to setup such a rule in ArcMap 10 Topology that Line Feature Class features shouldn't overlap with Polygon Feature Class features?
2
votes
0answers
473 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 ...
10
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2answers
725 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 ...
2
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1answer
155 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. ...
12
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2answers
8k views

How to check Topology in QGIS?

I have two Shapefiles with Polygons ( City and Forerst) Is there a Plugin who is able check the topology (QGIS)? Like "Knots do not overlap" or something like that? I dont want that they overlap. ...
8
votes
1answer
2k views

Splitting landcover polygons (parcels) into equal sizes, while retaining road access for all?

I would like to split landcover polygons which surround a road polygon into equal sizes, while ALL resulting polygons should have access to the road! Is there any chance to do this automatically? ...
5
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1answer
1k 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 ...
6
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2answers
8k 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
107 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 ...
4
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2answers
2k 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 ...
7
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1answer
580 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 ...
1
vote
0answers
103 views

From classified image to topology in ArcInfo

I have some coastal 4 band imagery that I have classified to designate land, water, and undetermined. I want to convert this to polygons with topology, and significantly simplify the polygons. If I ...
14
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5answers
2k views

Find pseudo nodes in free GIS software

Software gvSIG OA Digital Edition 2010 have tools topology for finding pseudo nodes in linear geometry. I set cluster tolerance 0.00002 and maximum number of errors -10000 for 20000 link count linear ...
15
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2answers
2k views

How to generalize SpatialPolygons and conserving topology in R?

I would like to generalize a SpatialPolygonsDataFrame in R to make plotting more efficient. The polygons I have result in huge pdf plots that are slow to load and hard to integrate into a document. ...
3
votes
3answers
1k views

Cause of selected [ArcSDE 10] feature dataset does not contain any feature classes which can participate in topology?

When trying to create a topology for a polygon feature class in ArcSDE 10. I right click the feature dataset that the feature class resides and try to create a new topology. I get an error saying, "...
4
votes
1answer
325 views

Is there a standard st_relation_readable() function for translate DE-9IM strings?

Spatial databases, such as PostGIS, implement the DE-9IM model with function st_relate(), which returns a string with domain of {0,1,2,F}, meaning 0=point, 1=line, 2=area, and F="empty set"... See DE-...
8
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2answers
745 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 http://arcscripts.esri.com/...
6
votes
1answer
2k 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
votes
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 ...
3
votes
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 ...
2
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4answers
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 ...
4
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2answers
1k views

Is there website with list of common QA/QC errors?

As I am working on reviewing my soils spatial data, and I am doing my QA/QC I placed a point layer to check for errors. I add the field column to mark the error and state the error. I recently ...
27
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5answers
4k 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 ...
0
votes
1answer
3k 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
719 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 ...
1
vote
1answer
142 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 ...
4
votes
3answers
1k 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
1answer
6k 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 ...
13
votes
4answers
3k views

How to connect lines in a network?

I have a shapefile of lines and another of polygons. When two or more lines intersect a polygon they should be connected (snapped), but sometimes during manual digitization this doesn't occur. I need ...
4
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5answers
3k views

How to select all dangling polyline features with Arcview license?

I have a city roads shp file and would like to identify (select) all the locations where a roads ends (in other words dangles). I am working in ArcView 10. I do not want to use a topological tool ...
3
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1answer
360 views

SDE Topology dirty areas don't go away

Just looking for an explanation on SDE Topology dirty areas that don't go away. My workflow involves editing a version of SDE data, then once finished I use the Validate Topology in Current Extent ...
12
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5answers
2k 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 ...
18
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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 ...
4
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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, ITopologicalOperator)...