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.

learn more… | top users | synonyms

3
votes
1answer
186 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 ...
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 ...
6
votes
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
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 ...
2
votes
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 ...
4
votes
2answers
255 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 ...
14
votes
2answers
1k views

How to generalize a polygon file and maintain topology in QGIS?

my problem: I have a polygon-file in shape-format, which I need to generalize. How can "split" the polygons into lines, generalize and than "rebuild" the polygons, so that I can ensure, that there are ...
0
votes
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 ...
1
vote
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 ...
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
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 ...
11
votes
4answers
2k 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
votes
5answers
2k 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
votes
1answer
219 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 ...
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 ...
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 ...
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, ...
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 ...
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 ...
8
votes
2answers
4k views

Why Intersect gives ERROR 999999: Error executing function Invalid Topology [Too many lineseg endpoints]?

I am trying to run an Intersect process in arcgis 10 sp 3 with 2 file sets (aspect and slope) from up to a 1m DEM across an area of 65,000sq km. The aspect has 9,930,384 records and the slope has ...
2
votes
2answers
450 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 ...
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
955 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 ...
2
votes
1answer
240 views

Convert SmallWorld GIS topology to pgRouting topology

Is there any way to convert SmallWorld GIS topology to the format that pgRouting use? My costumer have use SmallWorld GIS and make his topology on it. but when he export his information as shape file, ...
10
votes
7answers
1k views

How to identify polygons with “flag” sliver errors

Working in ArcMap, I have come across errors in a polygon layer that I will call "flag slivers" (taken from similar language in parcels call "flag lots"). These sliver polygons (see image below) are ...
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 ...
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 ...
8
votes
2answers
876 views

How to preserve topology while editing polygons in OpenLayers?

I’m facing this issue: I have a chloropleth map based on a set of polygons with some data. Using WFS-T (postgis, geoserver, openlayers) I am able to edit the geometry of the polygons. This works fine. ...
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 ...
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. ...
2
votes
3answers
836 views

Batch fix overlap errors

I have a feature class with about 250,000 contiguous polygons. ArcEditor turns up around 9,000 overlap errors when I validate the topology. I want to merge each of these errors into one of the ...
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
votes
2answers
557 views

topology problem

Can anyone tell me how to fix an error after running the topology rule in ArcGIS? I tried to subtract and create a new layer, but a failed warning appears every time.
1
vote
0answers
261 views

topology rules for structuring topology data to get line feature as topoparent in topology graph

i Created topology graph of a polygon feature and i copied geometry of topology edges into line feature class,and topology nodes into point feature class i created topology layer containing ...
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 ...
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 ...
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 ...
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
votes
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 ...
3
votes
1answer
672 views

Converting ArcGIS topology rules file (*.rul) to *.txt, *.csv or *.xls for reviewing?

Has anyone converted ESRI's topology rules file (.rul) into another format? I built a complex topology rules set and would like to QC it in something easier to read and work with than ArcCatalog. ...
1
vote
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?
9
votes
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?
8
votes
8answers
2k views

How to build topology without an ArcEditor or 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 an ArcView standard ...