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

0
votes
1answer
23 views

Access a topology sample code runtime error when define ITopologyExtension

I encountered a runtime error when I used the sample code from ESRI on Accessing a topology. The sample code is as follows: Dim topoUiD As UID = New UIDClass topoUiD.Value = ...
1
vote
1answer
21 views

How to generate pgrouting source and target with OSM?

Is there anyone here can explain me more details for pgrouting's source and target? I'm wondering how to generate with the given lonlat in OSM PostGIS entities. In pgrouting's website, they are ...
1
vote
0answers
15 views

vb.net arcobjects “current no topology available”

I am using ArcMap add-in to perform a topology validation. I have defined a topology in the geodatabase and add it in ArcMap TOC. When I try to get the current topology using ArcObjects, I get this ...
0
votes
2answers
49 views

How to set the tolerance value in pgr_createTopology function of pgrouting?

I am making a map based on the floor plan of a building. I made the shapefile and added it to the PostgreSQL database. I created the topology for the map using the following code: SELECT ...
0
votes
0answers
23 views

Can arcobjects validate topology globally

I want to develop a function which allow user to validate a topology in the whole map wide. But from what I searching from internet, to validate a topology, a dirty area (polygon) must be defined, ...
0
votes
1answer
20 views

vb.net arcobjects validate topology ITopologyExtension and esriTEEventHint not declared

I am trying to use arcobjects with vb.net to validate a topology (already defined). I am caught even when I use the sample provided by ESRI. The code I use for accessing a topology is: Dim topoUiD ...
0
votes
0answers
80 views

What does pgr_createTopology() expect for a table parameter?

In this sample http://docs.pgrouting.org/2.0/en/doc/src/developer/sampledata.html#sampledata there is this function: SELECT pgr_createTopology('edge_table',0.001); I understand that this creates a ...
1
vote
2answers
45 views

Software to detect intersections (within a tolerance) between 3d polylines

Is there any way to detect intersections (within a tolerance) for a 3d set of polylines? ArcGIS Topology Check seems to project everything into 2d (x-y plane) before checking, so shows a lot of false ...
0
votes
0answers
14 views

v.clean in QGIS Python console

I have tried to use v.clean and v.clean.advanced (by GRASS GIS) within a script in QGIS, and was not able. I followed instructions here:, but was not able to do so. I got message: "No module named ...
-1
votes
2answers
558 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
1answer
50 views

PostGIS: Update child geometries based on parent

I'm using Leaflet and postgis in a case where using Leaflet draw plugin I draw a polygon first like this Now, I draw a line which cuts the polygon and using line and polygon geometry, based on ...
3
votes
1answer
674 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. ...
6
votes
1answer
62 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 ...
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 ...
2
votes
1answer
42 views

Spike finder in PostGIS

I tried to modify spikeRemover from Schmidt & Krüger. My goal it's to obtain, for each polygon, the position of the spikes. I don't need to remove it. For some reason, that I can't figure out, my ...
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
1answer
68 views

What is a pseudonode?

I have been asked to check for pseudonodes - none are allowed for streams but they are for roads. I can't figure out why so I assume I am not understanding what a pseudonode is. I thought it was a ...
1
vote
1answer
25 views

In ArcGIS 10 - how do I clip an arc

I have an arc that has violated the topology rule that the road feature should not extent outside of my boundary. I tried to use the clip tool in editor but cannot complete the clip. I should be able ...
1
vote
1answer
54 views

Locating 0-points multipart polygons using arcpy

By Running this piece of code: import arcpy arcpy.env.workspace = "C:\working\GEODATABASES\\tests.gdb" fcList = arcpy.ListFeatureClasses() for fc in fcList: with arcpy.da.SearchCursor(fc, ...
3
votes
3answers
685 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, ...
8
votes
1answer
864 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? ...
-1
votes
1answer
39 views

check and validate the topology relationship between 2 feature class by concurrent users

my reqirement is allow several users to edit the map and validate the topology relationship between 2 feature class. Michael mentioned in my previous questions that I can only validata a topology when ...
0
votes
1answer
27 views

arcpy to handle topology error inspector

I am now want to do topology check use python, but I don't know whether arcpy can realize the function in error inspector. May I call error inspector and get the error records(something like attribute ...
0
votes
1answer
45 views

Can I validate topology using python script when ArcMap is open?

I am testing on validating topology using python.The situation is when I run the script when arcmap is open, an error occurs which indicates the topology has already been opened (FDO error: ...
2
votes
1answer
120 views

How can I make the topology checker plugin ignore very tiny errors?

I'm a QGIS2.0 user. Topology checkers is a very valuable for me as a data creator. I use this plugin for checking data quality. But, this plugin finds too much errors include very, very tiny ...
0
votes
1answer
65 views

Where can I find topology-related algorithms used in QGIS?

I have shapefile with polygons and I test topology - overlaps, duplicates and gaps. I tested it in QGIS and now I have to describe algorithms, which uses QGIS for this rules. I must write research ...
8
votes
2answers
879 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. ...
4
votes
1answer
102 views

PostGIS table to network analysis

I use PostGIS 2.0 and Python API (GeoAlchemy) to work with it. I want to convert topological informations (points, lines, faces) from PostGIS tables to topological network (points, lines) to study it ...
0
votes
1answer
41 views

Adding Rules to Topology with Arcpy: getting ERROR 000714

I want to make a very basic python script, however I keep running into error 000714 (general/unknown script error). The topology is created, the features are added to it, however the rule is not. ...
5
votes
2answers
358 views

I would like to know how to clean topological errors

I am a new QGIS 2.0 user. I was so impressed the new default tool, Topology Checker, in this new version. But, hundreds errors are bothering me for cleaning up features. Is it possible to clean ...
5
votes
1answer
132 views

Is there Open Source equivalent to ArcGIS Integrate (for topology correction)?

I need to transform a set of polygons so that it forms an exact spatial partition/tesselation (no gap - no overlap). What are the existing open-source solutions (software or library) to perform this ...
2
votes
2answers
112 views

How to check if vertex exists (on polyline) based on location of point layer using ArcPy?

Using ArcGIS for Desktop Advanced 10.1 (with all extensions) I am building a centerline network that will be used by a MapObjects program to do routing based on "turns at any vertex" (as opposed to ...
0
votes
0answers
17 views

Point in Linefeature build through specific topology rules

i want to build Lines from Point Features following different topology rules (that lines aren't like randomly build, but how i should be following the extent from other polygons for example.. when ...
7
votes
3answers
3k views

How to analyze differences between two shape files and put results into a new shape?

I have two polygon shape files of the same region from two different years (1985 and 1997) and I need to analyse the differences between the two shapes resulting in a third polygon shape file ...
14
votes
5answers
1k 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 ...
2
votes
2answers
453 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 ...
1
vote
0answers
53 views

Batch Clip (Editing Session)

I'm trying to correct some topology errors in my geodatabase, now focusing on two feature classes: grass and buildings. They must not overlap. However, there are plenty of spaces where the grass was ...
1
vote
1answer
40 views

How to edit line and polygon layers at the same time?

I have two layers, lines and polygons. Lines are basically the boundaries of the polygons. Is there any way that when I change or reshape the lines the polygons get updated automatically? I normally ...
3
votes
1answer
67 views

T-shaped polygons

Is there any coefficient that can indicate T-shaped polygons ? Examples of T-shaped polygons :
1
vote
0answers
96 views

How to simplify a self intersected / self overlapped polyline using ArcObjects?

I have a self intersected polyline, how can I break it into 5 records stored in the same table using arcobjects? (splited by vertices and the intersection point) Here is what I have got and it ...
3
votes
1answer
68 views

Verifying the number of times a line crosses other lines

I have a series of lines that represent streams. I have a stream line and two flowpath lines in one feature class and two banklines in another feature class. Total of five lines. I then have a feature ...
1
vote
0answers
57 views

How can I edit spatial data automatically on postgis and check for topology errors on said data whitout using shapefiles?

So, I have spatial data stored in postgis (points, lines and polygons) and would like to edit and update those in an Open Source software (quantum GIS, grass, etc.) to check for topologic errors, ...
2
votes
1answer
150 views

GRASS - v.clean Conflation - How to snap a layer to a base layer

Someone told me in this post that GRASS GIS can handle multilayer topology, what I have not found any information about. I am not a specialist of GRASS GIS so I would need help with that if its really ...
0
votes
0answers
38 views

Topology rules for a 3d network

I am currently writing a spec to which people may end up using to guide the digitization of a large 3d network (exterior pedestrian network + building interiors). In 2d network drawing, it seems to ...
4
votes
1answer
300 views

Topology problems with QGIS/GRASS

*edited file links below I'm working on several NGO projects at the moment, all of which are reliant on being able to use a district level map with some 490+ features, and I am running into some ...
0
votes
0answers
60 views

Dissolve a Geometric Network in ArcGIS

I have a geometric network of water mains in ArcGIS. It it composed of a line feature class. I would like to dissolve it based on whether line segments share common endpoints only. So basically ...
3
votes
5answers
603 views

How to Identify and Delete duplicate vertices?

I am trying to figure out how to delete duplicate vertices. I have successfully determined that there are duplicate vertices using PLTS Data Reviewer, but I am confounded as to how I identify and ...
1
vote
0answers
40 views

How can I build a network from a latitude, longitude points? [closed]

How can I build a network from a latitude, longitude points? I have some points(latitude and longitude) and i wish to build my network based on this points.
0
votes
0answers
41 views

Is it possible to compare two shape file if they have overlapped and gap between two data or not in QGIS

I am QGIS 2.0 user. I would like to compare two different shape file in the same region. This two shape file's outside border must be the same position. It means the overlap and gap must be zero. In ...
2
votes
3answers
107 views

How to correct topology on a shared boundary by removing nodes from a feature?

Maybe you can help me solve a problem regarding topology cleanup that I recently came a cross. I have two layers with bunch of polygons (or feature classes as I'm in the ESRI world) that should share ...