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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100 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 ...
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15 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 ...
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42 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 ...
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1answer
33 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 ...
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2answers
27 views

How to set the tolerance value in pgr_createTopolgy 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 ...
3
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1answer
53 views

T-shaped polygons

Is there any coefficient that can indicate T-shaped polygons ? Examples of T-shaped polygons :
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0answers
39 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 ...
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0answers
34 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, ...
3
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1answer
58 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 ...
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24 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 ...
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1answer
69 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 ...
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40 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 ...
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0answers
35 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.
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35 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 ...
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0answers
28 views

The topology cannot be validated because it is checked out

when I try to validate an existing topologiy in my personal GDB I got this error "the topology cannot be validated because it is checked out". How to solve it? thanks! It is a personal GDB. I'm ...
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0answers
52 views

What the pgr_createTopology() expect from a table param?

In this sample http://docs.pgrouting.org/2.0/en/doc/src/developer/sampledata.html#sampledata there is this struction SELECT pgr_createTopology('edge_table',0.001); I understand that create a topology ...
5
votes
2answers
130 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 ...
2
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3answers
74 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 ...
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0answers
85 views

Vertex and Nodes Tool - Migrating from 9.3.1 to 10.2.1

A previous employee built a custom tool for users in our organization that displays nodes and vertices when editing. Essentially the purpose is: The Display Topology Nodes button will symbolize the ...
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4answers
128 views

Is there a way to snap to apparent intersections in ArcGIS 10.1+?

Suppose there are two lines in an ArcMap 10.1 or 10.2 editing session that cross but do not intersect, per se. This is the case when new lines a drawn. Is there a way to snap to the point where the ...
2
votes
1answer
53 views

measuring adjacency between polygons

I am working with some land ownership data. I would like to identify parcels the have small adjacency between other parcels. In a nutshell I want to identify where there is a small overlap between ...
3
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2answers
77 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 ...
5
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0answers
66 views

What PostGIS [topology] provided tools may be used for data quality assurance?

I'm learning about techniques to ensure GIS data quality. Googling around, I've found a few papers about theory and best practices (here and here), and a couple of short presentations about the topic ...
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2answers
158 views

Doubts about how pgRouting topology is built and how flexible it is

I'm learning pgRouting, to validate if it can be used in a project. I have several doubts. Mostly related with how could I "fill the gap" between the "bricks" it provides and the real world ...
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0answers
67 views

Is there a way to build topology and work with topology relations in PyQGIS?

Is there a way to build topology and work with topology relations in PyQGIS? I'm asking because I need to run some custom generalization algorithms on my data, and I need to preserve topology. ...
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1answer
108 views

Insert Vertex into Polyline based on Point layer using arcpy

This is essentially the same question asked here that was not answered... Using ArcGIS 10.1 Advanced I have a point layer with points that represent the intersection of a driveway with a street ...
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1answer
60 views

ESRI ArcMap Topology rules on multi story buildings

I would like to run some topology rules to find snapping errors in our polygons but I am running in to the problem where we are working on multi story buildings with every polygon regardless of floor ...
5
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2answers
169 views

What's the difference between hypsography and topography?

I've recently come across some data that has been labeled "hypsography". I looked it up and it sounds like topography. But this data source has data labeled "topography" separate from its ...
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vote
1answer
99 views

Problem when creating database based on template_postgis

I have created a PostGIS template but when I try to create a database based on this template this is what happens: Connecting to the template: \c template_postgis; You are now connected to database ...
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votes
5answers
404 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 ...
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0answers
50 views

Delete polygon underlap?

I am editing a layer in QGIS with severe polygon overlaps. Is there a way to delete the underlapping portions (i.e. the invisible parts) using QGIS? If I import the layer into GRASS using the ...
6
votes
3answers
669 views

How to fill a hole in a multi-polygon layer on QGIS 2?

I need to fill a hole in a multi-polygon layer on QGIS 2.0. I've set the snapping option for the layer as follows : mode: to vertex and segment tolerance 4 pixels avoid intersection "enabled" ...
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0answers
57 views

Is the TIN created out of several cross sections different from merging the TINs created out of each set of two cross sections?

I have a river with cross sections that have the water surface elevation values. I am trying to create TIN from the water surface values and then compare it with the topo (to see the flooded areas). I ...
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0answers
26 views

QGIS : copy/paste with “Avoid Intersection” option

I need to copy and paste polygons from one layer to another but with adjustments in the pasted geometries: I need them to be cut in the same way they would have been cut by a single edit with the ...
2
votes
0answers
152 views

GeoDatabase topology and rules with a *.rul file

I have been working for some time on a solution to a problem much like this question. I have several layers that I want to resolve together. I have them all in topology (geodatabase) and have been ...
11
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2answers
476 views

What is topojson and how is it different than geojson?

This is a conceptual question. What are the differences between these? and what are the pros and cons of these formats?
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3answers
177 views

How to identify misaligned corners in PLSS sections

Sometimes PLSS section corners do not align How could I automate the detection of these corners and generate a new shapefile showing where this occurs? I have a shapefile of 147k section polygons ...
1
vote
1answer
93 views

ArcView: Trim polyline, that is shorter than specific dangle length (alternative to tool: Trim Line)?

I am looking for a way to trim dangles from a polyline shape, that are shorter than a specific length like the Trim Line Tool for ArcEditor and ArcInfo, but with ArcView-License. I already discover, ...
2
votes
1answer
135 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 ...
9
votes
2answers
408 views

Are there Desktop GIS alternatives to ArcGIS 10.X for topology and vector conflation?

Is there any options other than ArcGIS for Desktop for topological rules and automatic topology integrity enforcing in a Desktop GIS? I am looking for something that will automatically snap features ...
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0answers
222 views

JTS - Java Topology Suite - Calculate radius from a given point

From point A, I want to check if a point B is within a certain radius from A. How calculate it usindo JTS? I tried this: Coordinate posicaoAtual = new Coordinate(-12.974900375893823, ...
2
votes
1answer
118 views

Tools/Script to reshape automaticaly topologic edges within a given distance in ArcGis 10?

I have a footprint feature class and a land use cluster feature class. I am looking for a method/tool/script that would allow me: to reshape two edges into one (topologically) to decide at which ...
3
votes
2answers
295 views

Create a network topology for pgrouting with grade separation

I have built a network using Ordnance Survey's ITN data and I can solve routes across the network. What I need is to build in grade separation topology for overpasses and underpasses on the network so ...
3
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0answers
177 views

How to create a topologically correct dataset in PostGIS (with GRASS)?

I have shapefiles which I have loaded in postgis and now i am trying to use geometric function in postgis like ST_intersect and they fail because the data is not topological correct. I have tried to ...
0
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0answers
246 views

Possibly corrupt polyline file is causing making polygons problematic.

I used the Feature Class to Polygon tool in ArcMap 10.0 to create a polygon from a polyline shapefile and some polygon boundaries (polylines) are disappearing in the process. The polyline shapefile ...
2
votes
0answers
98 views

Joining layers with respective elements with PostGIS Topology

Recently I have started using PostGIS topology extension, but I have some difficulties in understanding how the structure works: One of the key points is the use of "layer"s: as of what I understand, ...
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3answers
343 views

Snapping start- and end nodes of lines to other lines in PostGIS

There are plenty examples that show how to snap lines to points, but I haven't been able to find any (fast!) way of snapping the start- and end nodes of line strings to nodes of other lines. ...
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3answers
330 views

How to clean layers from non topological databases?

I'm doing my internship in a consulting office which is switching from MapInfo to QGIS/GRASS 1.8.0. I posted here a few days ago about the way to clean a polyline from a Lidar data with v.clean. ...
4
votes
1answer
355 views

How to repair and clean contours from high data resolution (lidar)?

I'm unsuccessfully trying to make a bathymetric map with contours extracted from Lidar data at 1 m resolution. The extracted contours have a lot of artifacts like dangles and islands. First I used ...
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0answers
59 views

generate hydro network topology on a stream network

I want to generate hydro network topology on a stream network without calculating catchments and drainage points. My initial data are a Line layer (river network) and a DEM10 and the target is to ...