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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26
votes
4answers
6k views

Simplifying adjacent polygons using PostGIS?

I encountered a problem simplifying set of polygons that are adjacent. If I simplify each polygon separately with the Douglas–Peucker algorithm (which is used by many open source tools), the resulting ...
12
votes
3answers
37k views

Merging adjacent polygons using ArcGIS Desktop?

I want to use ArcGIS Desktop to merge adjacent polygons with each other. There is no common field between the polygons and hence the Dissolve tool is not the ideal solution. The polygons that I want ...
12
votes
3answers
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,...
8
votes
1answer
2k views

Creating Multi-Part Polygons that touch internally using ArcGIS Desktop?

I have a set of parcels as illustrated in the image below. There are currently no multi-part features in dataset. What I would like to do is to merge (not the right word) all of the parcels with same ...
7
votes
6answers
1k 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 ...
6
votes
2answers
172 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 &...
5
votes
1answer
1k 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 ...
5
votes
1answer
134 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 ...
4
votes
5answers
2k views

How to test whether two countries are adjacent using ArcGIS Desktop?

I have an interesting question: Is there a dataset by which I can use to test whether two countries are adjacent? For example, if inputs are Mexico and U.S., they are adjacent; if inputs are England ...
4
votes
4answers
152 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 (...
4
votes
1answer
198 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, ...
4
votes
3answers
271 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 ...
3
votes
1answer
163 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 ...
3
votes
1answer
856 views

Extracting polyline of border between differing polygons using R or GRASS?

I have a shapefile with polygons with an associated variable that can take different values. I would like to extract the borders between polygons of differing value (red and blue) as a polyline (dark ...
3
votes
2answers
124 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 ...
3
votes
0answers
94 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 ...
3
votes
0answers
449 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 ...
3
votes
0answers
190 views

Adjacency matrix for polygons using Java

I am trying to create an adjacency matrix from a set of polygons. That is, I have a bunch of polygons and I want to identify which polygons have a common edge or "touch" each other. Once I find this ...
2
votes
1answer
154 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 ...
2
votes
3answers
1k 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 ...
2
votes
1answer
3k 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 ...
2
votes
1answer
651 views

Adjacency matrix from polygons in GeoJSON

I have a set of polygon features in a GeoJSON file. They are neigbourhoods in Chicago. I would like to produce an adjacency matrix A, in CSV format or any other form, where the i,j element of A is 1 ...
2
votes
1answer
196 views

Adjacency matrix from TopoJSON

I have a TopoJSON file which describes electoral districts in Montreal, and I would like to produce an adjacency matrix which would tell me which districts share a boundary with which other districts. ...
2
votes
1answer
89 views

Trying to extract arc information from a Suburb shapefile

I downloaded some shapefiles from the Australian Bureau of Statistics (ABS). It's basically showing a bunch of suburbs when I view the shapefile through a GIS tool. The GIS tool that I am using at ...
2
votes
0answers
120 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 ...
2
votes
0answers
78 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 ...
2
votes
0answers
248 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 ...
2
votes
1answer
173 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 ...
2
votes
0answers
63 views

Specifying polygon face toward two different lines using ArcMap?

I have a parcel layer, a street of city layer, and I want to find the parcels at the corner of two different streets (meaning a house with two faces toward 2 streets). I am using ArcMap. I want ...
1
vote
2answers
336 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 ...
1
vote
4answers
742 views

Adding information about adjacent features to data using ArcGIS Desktop?

I am working with ArcGIS 10.0. As a simple example let's say I have a map of the United States. I want to each row of the data which states have adjacent boundaries with that state - so that in the ...
1
vote
2answers
264 views

Adding/updating field to polygon feature class that lists bordering (neighbor) polygons?

I have a dataset of zipcodes. I want to add a new field "NEIGHBORS" that includes bordering polygons in a comma delimited manner such as attached image:
1
vote
2answers
212 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?
1
vote
1answer
435 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 ...
1
vote
1answer
31 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?
1
vote
1answer
213 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 ...
1
vote
1answer
45 views

Identifying ID of adjacent pipelines?

I work with ArcGIS. In the picture you can see several pipelines, more over pipeID's A; 1; 2; 3 I would like to have as an output the following columns and rows: A - 1; A - 2; A - 3; As an ...
1
vote
1answer
1k views

Creating lines that connect the centroids of adjacent polygons to one another

I have about 10 polygons, and I have added their centroids to the map. I want to create lines connecting the centroids of each adjacent polygon. If polygon 1 borders polygon 2 and 3, I would like a ...
1
vote
0answers
36 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 ...
1
vote
0answers
163 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 ...
1
vote
2answers
483 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 ...
1
vote
0answers
52 views

Merge without dissolve in ArcGIS for Desktop? [duplicate]

I am trying to merge several polygons in a feature dataset into one. Normally I would use a simple merge but the issue is that merge automatically dissolves. I on the other hand want to have them all ...
1
vote
1answer
66 views

Outputting Polygon Neighbors into special format using ArcPy?

I need Polygon Neighbors to give me data in a specific format. Every polygon should have its own line in the output. Take this, for example(it's obviously not ArcGIS formatted, but it serves the ...
0
votes
2answers
174 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 ...
0
votes
1answer
202 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 ...
0
votes
1answer
110 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. ...
0
votes
1answer
56 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 ...
0
votes
1answer
60 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?
0
votes
1answer
427 views

Merge adjacent polygons [closed]

I want to write software that merges groups of (mainly) adjacent polygons. For example, merge the US counties into sales regions. Then, display either the boundary of these sales regions or fill them ...
0
votes
1answer
864 views

Merge touching polygons with keeping their attributes

I've got a layer of polygons Although they all in the same layer, each polygon own some unique data like the date of this polygon and an amount it possess (a number). I want to join/merge all the ...