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Questions tagged [adjacency]

Spatial relationship where two features share a common border under some interpretation - ie, are 'next to' each other.

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5 votes
3 answers
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Creating list of adjacent polygons in QGIS

The answer to Using join in Mapviewer describes an effective way to count the number of adjacent polygons. However, I need to create a list of the adjacent polys. I envision a process that generates ...
Stu Smith's user avatar
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3 votes
1 answer
248 views

How do I merge/dissolve two polygons within one shapefile in QGIS?

I have a shapefile composed of many polygons. I want to merge/combine/dissolve some adjacent polygons that I have selected within the shapefile into one polygon without any slivers or lines left in ...
MapDeath's user avatar
  • 343
3 votes
1 answer
76 views

Make line from each polygon centroid to each adjacent polygon centroid in QGIS

In QGIS I would need a Geometry Generator expression to, from a polygons layer, draws a line from the centroid of each polygon to the centroid of each adjacent polygon
Nil Aspinall's user avatar
0 votes
0 answers
38 views

Identifying features that are surrounded by a certain dimension of another polygon in ArcGIS Pro

I am currently working on a project where I have two polygons files overlapping each over - Polygon A (blue) overlaps Polygon B (green). I would like to be able to identify the individual "blue&...
user54694233513's user avatar
0 votes
1 answer
625 views

Determining adjacency across elements in a GeoPandas GeoDataFrame

Main question What is an efficient (i.e., good balance of memory & processing time) way to compute adjacency using a GeoPandas GeoDataFrame? For my the rest of my question, I'll focus on the case ...
Felipe D.'s user avatar
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6 votes
2 answers
450 views

Counting adjacent polygons using QGIS

Is there a way to count adjacent polygons using QGIS? I want to create a new field with the number of adjacent polygons. I want to count adjacent polygons to determine if a polygon (house) is a corner ...
Sander Van Beuningen's user avatar
3 votes
1 answer
238 views

Are contiguity matrix and adjacency matrix the same?

I'm am sorry for that beginner question. To start the calculation of a spatial auto-correlation value, the book I'm reading writes that we will starting to construct a contiguity matrix. Looking at ...
Marc Le Bihan's user avatar
1 vote
0 answers
65 views

Comparing two sets of polylines intersecting polygons and get a matrix of gained/lost connections [closed]

I have three feature classes, one is of Polygons and the other two of Polylines, representing a set of areas in a city and a network of transit lines between those areas - one network for current ...
Guy R.'s user avatar
  • 19
2 votes
0 answers
56 views

Style rule based on feature adjacent edges and ignore vertices

I have a set of square tiles which I want to show in a different colour when the tile to the north, south east & west are present in the same way as below with the links I want in black. I have ...
Chris's user avatar
  • 21
0 votes
0 answers
153 views

Normalize distance between U.S. counties so that adjacent counties are unit distance away

High level problem: I'd like a "distance" metric that measures adjacency rather than euclidean distance. Details: I'm looking for a way to normalize distance between U.S. counties so that ...
Sal's user avatar
  • 101
1 vote
1 answer
49 views

Adjacent polylines subtraction [closed]

I have road segments that have slope values. I want to find the roads with the largest grade changes between neighboring segments. How do I go about doing that in QGIS?
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4 votes
4 answers
1k views

How to find neighboring polygons which share a common feature in ArcMap 10.4?

I am currently using ArcMap 10.4. My task is to find which polygons share a border given a specific feature. I would like to automate this workflow. For instance, I have 2 polygon feature dataset (...
Monitotier's user avatar
0 votes
0 answers
44 views

Querying Adjacent Polygon Features using ArcMap

I have a layer of polygon features representing forest stands with a vegetation type and age. For every forest stand I want to assign it a value in an empty field if any of the adjacent stands have a ...
Erich Ostendarp's user avatar
0 votes
1 answer
231 views

ArcGIS Pro matching and dissolving neighbours

I have a FeatureClass derived from ArcGIS Desktop 10.6.1's Polygon Neighbors tool [Windows 10 - 64]. I have supplied a tiny sample (of >250k) that gives the flavour and an example of the objective. ...
Bruce Mitchell's user avatar
2 votes
2 answers
743 views

Extracting lines from polygons/buildings based on adjacency to lines/streets

I have a building and street shapefile of a district. I am looking for a way to select and eventually extract those lines or edges of the buildings that face the street. however the extracted edges ...
murph21's user avatar
  • 29
0 votes
0 answers
603 views

Problems with adjacency matrix with poly2nb in R

I am working with a shapefile of Ohio precincts, with the hope of performing areal regression models (probably BYM2). To build the adjacency matrix, I used poly2nb from the spdep package. As a double-...
St4096's user avatar
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1 vote
1 answer
288 views

Filtering polygons that share more than 2 vertices using QGIS

Is there a way to filter polygons that share more than 2 vertices with a feature? I have multiple polygons, like in the image, but I just want to see those that touch more than one vertex of the main ...
Felippe M.'s user avatar
  • 1,082
0 votes
1 answer
107 views

How to increase the number of the adjacent cells of a focal cell?

I want to recover the adjacent cells around a focal cell, I could do it by using the function adjacent form the package « raster », cells_adj <- adjacent(Habitat[[1]], cells=cells_xy, directions=...
user2300's user avatar
6 votes
2 answers
340 views

Why do clipped polygon features (clipped with adjacent polygon tiles) still overlap with each other?

I have two layers in QGIS with intersecting polygons (blue "P1" and green "P2"). I want to clip them with adjacent polygons tiles (dotted line - blue "cut1" and green &...
Jakub Rusnák's user avatar
0 votes
1 answer
146 views

Polygon Neighbors tool produces incorrect results

BACKGROUND: At 10.8.1, I have used the Polygon Neighbors tool with a countywide parcel shapefile (approximately 47,000 polygons). The tool runs to completion (taking < 1 minute) without reporting ...
Stu Smith's user avatar
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0 votes
2 answers
692 views

Identifying shared polygon boundaries in ArcGIS Desktop

I am aware you can dissolve boundaries (standard feature analysis tool) but is there a way you can calculate polygons that share a boundary? I have attached picture with an example of the polygon data ...
GIS_BUD's user avatar
4 votes
3 answers
657 views

Simplifying adjacent polygons on subset of vertices only

We have many adjacent polygons which are very complex and we need to simplify only some portions of them. There are no gaps nor overlaps between any two adjacent polygons. What we'd like to do is to ...
Jivan's user avatar
  • 283
2 votes
1 answer
574 views

how to remove small water bodies in binary mask array that we get from ndwi values?

I've detected water bodies in satellite images (modis, sentinel, landsat) in special area polygons, by ndwi values and based on special thresholds. area polygons and image tiles are coordinate ...
Mehrdad HMT's user avatar
1 vote
2 answers
398 views

Checking if selected features are adjacent using OpenLayers [closed]

I need to be able to merge features on the condition that the selected features are adjacent to each other. How can I achieve this using Open Layers version 5?
orpheus's user avatar
  • 203
1 vote
0 answers
64 views

Adding attributes from surrounding feature (exclave problem)?

Here is the problem: I am creating polygons based on the result of closest facility tool in Arcmap. Polygons consist of municipalities with the same closest hospital (impedance is a travel time, not ...
Filip's user avatar
  • 41
0 votes
1 answer
329 views

Finding neighbouring countries using Overpass?

How can I find all countries that are neighbours (share a border point or line) of a given country (eg. germany) using Overpass?
GeoMapper's user avatar
0 votes
1 answer
66 views

Computing area of shared surface between adjacent 3D features in ArcGIS Pro?

ArcGIS Pro currently provides the Polygon Neighbors tool to compute the length of the shared border between features. I want to do the same type of calculation for (closed) 3D features, i.e. I want to ...
mikeck's user avatar
  • 181
2 votes
0 answers
201 views

Converting polygon to line with neighbor info using QGIS?

Is it possible to create lines from polygons with information about neighbors in QGIS? I would like to do this for land plots. There is a tool in ArcMap that works like a charm, but I do not see ...
Radek Nakielski's user avatar
2 votes
0 answers
136 views

Convert bitmap image to adjacency [closed]

I have a map in a bitmap image format (.bmp) where each region is assigned an RGB colour. What I want is a list of every adjacent region, for every region. So if region1 is adjacent to region2 and ...
Amélia's user avatar
  • 21
3 votes
0 answers
116 views

Grouping polygon neighbors recursively using PyQGIS? [closed]

I have a shapefile with polygons and need to group them with the same Group_ID if they touch each others. The thing is, once I start assigning a number to one polygon, it needs to keep looking for ...
AJMR's user avatar
  • 31
3 votes
1 answer
228 views

Ordering polygon neighbors in clockwise order using ArcMap

In ArcMap, I am using the Polygon Neighbors tool to generate a list of each polygon's adjacent polygons, or 'neighbors.' Currently, ArcMap orders the polygons using each polygon's numeric ID. What I ...
Anna Marie Vagnozzi's user avatar
1 vote
2 answers
704 views

Merging polygons that share one vertex (node neighbors) using ArcGIS Desktop?

I have a set of very large shapefiles and would like to merge polygons within these that share one vertex. Currently they are all separate like so: What tool can I use to merge all the polygons ...
tom91's user avatar
  • 115
5 votes
1 answer
3k views

Dissolve (merge) polygons QGIS based on attribute values only when are adjacent

I am a fairly new user of QGIS having a question regarding dissolve functionality. I am working with the NUTS-2 shapefiles provided by EU, which I have imported in QGIS. I have created a new layer ...
Cord's user avatar
  • 71
1 vote
1 answer
567 views

Using Polygon Neighbors for boundary polygons to find boundary lengths in ArcMap?

I am working in ArcMap. I have a map of districts in South Carolina, and I'm trying to find the boundary length that every district has with every other district, and the boundary of South Carolina ...
BSplitter's user avatar
  • 135
0 votes
1 answer
172 views

Second-level neighbors of large polygon (neighbors' neighbors)

I have a large-ish set of polygons and am after identifying second-level neighbors of each, that is, the neighbors of the neighbors of each polygon (distinctly, i.e. the 2nd-level neighbors cannot ...
MichaelChirico's user avatar
1 vote
1 answer
524 views

Extract the "mid/center-point" of the touching borders/lines of adjacent polygons

I have a layer with several polygons and want to extract the "mid/center-point" of the touching borders/lines of adjacent polygons. Despite trying several methods, I do not know how to achieve what I ...
JAT86's user avatar
  • 932
7 votes
6 answers
2k views

Determining if polygon not enclosed by other polygons [closed]

Does anyone know of a routine/function or transformer that would identify if a polygon is not fully enclosed/surrounded by other polygons? The polygons have no gaps or slivers between them so if a ...
tjmgis's user avatar
  • 3,330
0 votes
1 answer
217 views

Identifying/exporting adjacent polygons in ArcGIS Desktop?

I have many polygons (US Counties) with agricultural land data in them. I would like to identify and export (ideally into excel) the data from the counties that are adjacent to the ones with ...
Max Ewart's user avatar
0 votes
1 answer
77 views

Selecting coastal census tracts in ArcMap? [closed]

What tool should I use to select or identify geographic units that are adjacent to the U.S. coastline feature in ArcMap?
Amelia's user avatar
  • 11
3 votes
0 answers
758 views

Creating Adjacency Matrix using SpatialLinesDataFrame and SpatialPointsDataFrame in R?

I am trying to create an adjacency matrix of power plants that are connected via power lines. The plant data is point data (~8000 observations) with longitude and latitude measurements. The line data ...
Rachel S's user avatar
1 vote
0 answers
234 views

Directions based on polygon centroid and average/median point of adjacent polygon's touching border

I have a layer containing multiple polygons, and I am trying to find a way to identify the directions of the adjacent polygons of a certain polygon. The directions would be based on the main polygon ...
JAT86's user avatar
  • 932
2 votes
0 answers
306 views

Postgis List of adjacent LineStrings ordered sequentially from one end of the MultiLineString to the other

I have LineStrings that represent a road network/address centerline that are segmented at intersections, etc. I have determined how to query collections of LineStrings that are adjacent to each other ...
Alison Wieckowicz's user avatar
0 votes
0 answers
119 views

Calculate Adjacent Fields Issues

I am trying to run the Calculate Adjacent Fields ToolBox on one of my Shapefiles, but the process is taking hours to run, and I have yet to complete the process. My table is 18,000 rows, and so far ...
Mwspencer's user avatar
  • 223
2 votes
1 answer
5k views

Merging adjacent polygons in QGIS

I have a set of polygon layers with thousands of polygons some of which are adjacent (Either rings or simply adjacent). I would like to simplify this polygons by merging them. Is there a way to do ...
C.-F. Vintar's user avatar
  • 1,616
2 votes
1 answer
215 views

Adjacency Matrix Not Including Vertices

I have a SpatialPolygonsDataFrame and I would like to create an adjacency matrix. However, I would like to only count two polygons as adjacent if they share more than just vertices (i.e. they share an ...
Scott's user avatar
  • 23
2 votes
3 answers
2k views

Counting polygon neighbours and writing to table using PyQGIS? [closed]

I have a shapefile with municipality polygons. I would like to count the number of neighbours for each polygon and write it to the attribute table. I have no succeeded yet in doing this, even though I ...
Mario's user avatar
  • 561
12 votes
3 answers
3k views

Conditional assignment of values to adjacent raster cells?

I have a value raster: m <- matrix(c(2,4,5,5,2,8,7,3,1,6, 5,7,5,7,1,6,7,2,6,3, 4,7,3,4,5,3,7,9,3,8, 9,3,6,8,3,4,7,3,7,8, 3,3,7,7,5,3,2,8,9,8, 7,6,2,6,5,...
Pierre's user avatar
  • 395
4 votes
1 answer
252 views

ArcGIS, detect adjacent polygons with different values

I am developing an ArcMap extension and I need to validate a particular case. I need to detect adjacents polygons that have one value equal, and the others not equal. I you take a look at the image, ...
Math's user avatar
  • 405
1 vote
2 answers
757 views

Identifying isolated polygons within other polygons ArcGIS for Desktop?

I am using ArcGIS 10.4 for Desktop. I have a single feature class with one attribute with 5 levels describing the state of grasslands and how they have changed over time. The attached image shows a ...
ChrisStockdale's user avatar
5 votes
1 answer
190 views

Style rule based on feature adjacency?

Is there a way in QGIS to use an expression to define a polygon feature's color based on whether it's adjacent to other features? I would like to achieve something like the following: -If a feature ...
Nathan's user avatar
  • 1,304