Questions tagged [topology]
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.
3
votes
1answer
27 views
Fixing self-connect polygon in QGIS 3.2
I'm trying to clip a soil map layer and am getting invalid geometry that affects my clip result. The problem appears to be a self-intersecting polygon.
I've tried using the 'check geometries', and ...
2
votes
0answers
49 views
Does GeoPackage support topology?
Does GeoPackage support topology?
I am looking for resources that discuss this topic in more detail.
I googled and did not come across good resources that discuss this question in detail. I could ...
0
votes
0answers
19 views
Topology rule to align two different feature classes
I am looking for a topology rule or geoprocessing tool that would align the blue feature class boundaries to the black feature class boundaries depicted in the following screenshot:
I could obviously ...
0
votes
0answers
21 views
Connecting line with polygon edge using ArcGIS Topology?
I have to connect many of these points with the edges of polygons.
I am using Topology, but the "must not have Dangles" allow to connect two lines together, not a polygon edge and a line.
Can ...
1
vote
2answers
56 views
Generate points along branching lines
I am looking to generate points along a series of connected lines at regular intervals, but I wish to keep this interval even when a line is branching into 2 or 3 other lines. All the regular tools I ...
0
votes
0answers
10 views
Surfer force topology checks on polygons
Is there a trick to force topology checks in Surfer or Didger? My polygons are in BLN (or sometimes DAT and just connect the lines in Surfer). When one gets updated (like in the sketch on the right), ...
2
votes
1answer
72 views
Adding vertices to multiple overlapping line segments in QGIS?
I have a polyline dataset of transit routes for my city. Around the transit stations, up to hundreds of routes overlap completely, but do not follow the correct path that the busses actually travel (...
3
votes
1answer
60 views
QGIS 3.4.4 snapping does not lead to expected topology and st_relate result
I try to snap a line to a polygon boundary. This is working fine, due using the snapping option in QGIS (snap mode vertex and segments & tolerance 0 pixels)
Line 1 is snapping to the polygon ...
0
votes
0answers
43 views
Hex grid of UK Local Authority Districts
I'm trying to generate a hex grid for UK Local Authority Districts (390 objects). The package geogrid produces this hex grid:
As you can see, the adjacency of the units is not guaranteed, and some ...
0
votes
0answers
16 views
Line sequencing error
I have clean topology, also validated, but when I am loading it I to parcel fabric, it shows line sequencing error, what can I do about it?
0
votes
0answers
18 views
How to add rules to the topology from a .rul in ArcPy
I am trying to create a new topology using and ArcPy script and I have a lot of rules inside a .rul archive. The function to do that is:
arcpy.AddRuleToTopology_management(out_topo, rule_type, in_fc1,...
1
vote
0answers
16 views
Disabling some topology rules temporarily to speed up checking other rules using ArcMap?
I am using ArcMap 10.6.
I have a topology with a large number of rules and many feature classes. I need to check only certain rules and feature classes and wondering the best way to do this without ...
4
votes
3answers
86 views
Seeking alternatives to Geodatabase to describe topological relations?
According to switchfromshapefile.org, there is no way to describe topological relations in a shapefile. I am aware that this can be done using a Geodatabase and I have heard of TopoJSON.
If there are ...
0
votes
0answers
32 views
Segmentation of a line based on several overlapping lines within the first line
I stumbled over a problem which I can't figure out myself so maybe you can help me..
I have a line going from 0 to 100% of its length. On this line I have 1:n lines with different information and ...
2
votes
1answer
51 views
Does parcel fabric have topology built in?
I am a little confused on parcel fabric. Does parcel fabric have a topology built in already? OR are you supposed to create a topology for your parcel fabric?
Just a little background is that I have ...
2
votes
2answers
69 views
Moving multiple points in batch using ArcGIS Desktop?
I have multiple parcel polygons and they all have one side touching the lake polygon. Each parcel polygon has a point inside which is now at the centroid of the parcel. I need to find a way to move ...
2
votes
0answers
35 views
PostGIS Simplification on topogeometry does not respect topology?
I'm testing the code in the book "PostGIS in Action" (2nd ed) on Topology-based Simplification:
DROP TABLE IF EXISTS _temp_table; CREATE TABLE _temp_table AS
SELECT feat_name, ST_Simplify(topo,150) ...
1
vote
1answer
27 views
How to reset the id number of newly generated PostGIS topology?
I'm trying to create a clean, new topology for testing by discarding the old topology first, i.e.:
SELECT DropTopology('ch13_topology');
SELECT CreateTopology('ch13_topology', 32610, 0.05);
However,...
0
votes
0answers
17 views
repeated TopoGeo_AddLineString creates multiple entries in PostGIS topology?
I just noticed something strange in PostGIS topology (PostGIS 2.5). When applying TopoGeo_AddLineString() to the same geometry multiple times, it creates more than one entries in the edge_data table.
...
2
votes
1answer
68 views
Cleaning topology errors in PostgreSQL (vector data) using QGIS?
I need to append the shapefiles to a PostgreSQL database. Once the data gets appended to PostgreSQL, some topology errors like gaps & overlaps can be seen.
By using the v.clean tools the topology ...
2
votes
2answers
41 views
Editing shared boundary of two polygons at same time using ArcGIS Desktop?
If there are two square polygons next to each other, sharing a boundary is it then possible to adjust the shared boundary so that the size of both squares change as opposed to making one square bigger ...
1
vote
1answer
33 views
Find Close Vertices in QGIS
I am trying to find digitizing errors in a line-layer. Obviously the snapping was not activated when the person who digitized created the lines.
As far as I know QGIS cannot find undershoots, so I ...
1
vote
1answer
51 views
More customizable topology options for QGIS
I'm working on a polyline network where there are a lot of open-ended lines that I do want, but also a lot that I don't. QGIS's topology checker flags all cases, making it a major hassle to go through ...
3
votes
0answers
54 views
Dealing with bridges over roads in PostGIS topology?
first time posting please ask for more details if not enough provided.
I am using OSM road data and have created postgres topology for them. I am now cleaning up the data before exporting it for ...
0
votes
1answer
47 views
Finding difference in gaps between polygon
I am using ArcGIS Desktop.
I have a feature class of polygons. At first I run topology with rule "must not have gap" error. I find 250 errors (these all are exceptions). After shifting all the ...
2
votes
0answers
131 views
Topology Network in PostGIS database
I'm returning to the same question all over again. I'm dealing with electrical network and I'd like to build topology for all network lines in database so I can construct nodes and edges dynamicly for ...
2
votes
1answer
38 views
Polygons split themselves when I zoom out
I've been having issues with polygons getting deleted and re-created in this layer, and also with polygons not merging the way I would expect. I thought I had everything fixed-- my topology check ...
0
votes
1answer
44 views
Remove overlaping vertices in lines - QGIS
I am currently working with data that has a huge amount of topological errors. These are lines that are closed, in the place where the beginning of the line meets the end, someone added more than 2 ...
2
votes
1answer
71 views
PostGIS topology hierarchal topogeometries
I'm seeking guidance on how to correctly organise hierarchal topogeometries.
I'm working through PostGIS in Action's chapter on topology and, in summary, it sets up two tables with topogeometries, ...
2
votes
1answer
314 views
How can I enable topological editing in QGIS 3
How can I enable topological editing (create shared nodes on adjacent polygons or intersecting lines) and also activate the option to prevent polygon overlap (that when a new polygon is drawn, its ...
0
votes
1answer
42 views
Connect points to lines so moving points moves line?
I'm trying to create a simple sewage system in ArcMap. I want it so that when I move a node/point, the line is moved as well so it needs to be attached to the point (dynamic link?).
A Point may have ...
1
vote
0answers
20 views
Deleted Topology and Feature Classes are still locked within Geodatabase
I deleted my topology within a geodatabase rather than disconnecting the feature classes inside of it. Doing this appeared to have deleted all 4 feature classes that were within the topology entirely ...
0
votes
1answer
87 views
ArcGIS Pro Topology - Fix multiple errors in one step through Inspector
Does someone know if it is possible to select multiple "error-features" in ArcGIS Pro Topology error inspector and fix all of them with the same solution (e.g. create new feature)? Currently in ...
1
vote
0answers
22 views
RoadLink and RoadArea topological relation in INSPIRE
I have some confusion about RoadLink and RoadArea topological relation in INSPIRE (Infrastructure for Spatial Information in the European Community).
If I got this correctly:
RoadLinks are connected ...
2
votes
1answer
61 views
Automatic cleaning of polygon overlap based on attribute in QGIS
I have a shapefile with overlapping polygons. I need to clean these overlaps based on an attribute: in case of polygon overlap, the polygon with the lowest value of a given attribute needs to be ...
1
vote
0answers
24 views
Checking snapping connection of polylines? [closed]
I would like to find a method using ArcMap that could check if all polyline are snapping and connected.
I tried to create road network, but I can see this information.
I have multiple polyline, and ...
1
vote
2answers
365 views
Checking if vertices of polygon are in clockwise or anti-clockwise direction in QGIS?
Is there a simple way to calculate a field in QGIS indicating if the vertices of each polygon feature in a layer are in clockwise or anti-clockwise direction?
For simplicity, lets assume the layer ...
0
votes
1answer
37 views
Adding ArcGIS topology rule that allows Attribute based exceptions?
I want to run a topology - one is geometry based where I am looking for overlaps as error, but in my database I want to keep some error as exceptions (such as road over waterbodies).
One option is ...
1
vote
1answer
53 views
Discerning dwelling types in QGIS? [closed]
In QGIS, I want to discern between a number of building types, based on topology. I have data on buildings, parcels and addresses.
I'm having a hard time to discern between row/terrace, end-of-...
6
votes
0answers
158 views
How do I select the longest connected lines from PostGIS ST_ApproximateMedialAxis?
I used PostGIS ST_ApproximateMedialAxis to transform polygons representing mountain ranges into a series of lines. Now, I'd like to select only the "longest" line segment for each group, so that I ...
0
votes
0answers
149 views
How to automate topology check/fix in QGIS?
Short version: I have a layer with 19483 features with plenty of topological errors and I would like to fix/review them as many as possible in an automated way but don't know how to do it. ...
0
votes
0answers
56 views
error 999999 add rule to topology management
I was trying to create a topology with some rule, but I have problems with the rule "Must Be Covered By Feature Class Of".
I get the error "999999: Error executing function."
This is the code:
WU =...
1
vote
0answers
30 views
Cannot Create Topology in SDE
I am trying create a topology for a zoning dataset in my SDE feature dataset. I've run into a few issues. First off was an issue with versioning that this questions resolved: How to solve "Cannot ...
1
vote
2answers
39 views
When topological editing how can I automatically snap lines to lines close to them?
Using ArcMap 10.3, advanced license, I have a data set of road lines and another data set of road surface conditions, and I need to apply the road conditions to the road line as an attribute where it ...
0
votes
0answers
29 views
Arcpy export topology errors bug
I have created an ArcGIS Python script tool that creates and validates a topology dataset, exports the topology errors and performs some analysis between the topology errors and their source feature ...
4
votes
1answer
81 views
Fixing bad topology on polylines with QGIS
I've been sent a shapefile containing 12 layers of some city's road system. Each layer depicts a portion of the road system, and all of them partially overlap on the map.
I'd like to work on the sum ...
1
vote
3answers
138 views
Align one polygon boundary to another boundary
As visualized in the picture as an example, two polygons should be aligned to each other. The boundaries of the green polygon should not be changed. The blue polygon may therefore only be adapted to ...
0
votes
0answers
57 views
Handling dangling nodes in ArcGIS Desktop?
I have a datafile of line features. The creation of a topology revealed that there are too many dangling nodes to be corrected manually.
I was thinking of snapping to the closest line feature in an ...
3
votes
0answers
124 views
ST_Difference in PostGIS : problem with geometry result (Polygon)
I'm experimenting a result issue using the ST_Difference spatial function in PostGIS.
Input :
Feature 1 and 2 overlaps each other. Both contains 5 vertices, like a rectangle (4 plus an additional ...
2
votes
1answer
313 views
Repairing all topology errors at once in ArcMap?
In 2012 an ArcMap user wrote Automatically fixing multiple errors using Fix topology error tool?:
I am a ArcGIS.10. user. I'm want to solve multiple errors using the
fix topology error. So I ...
