Questions tagged [polygon]

On a map, a closed shape defined by a connected sequence of x,y coordinate pairs, where the first and last coordinate pair are the same and all other pairs are unique.

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Are there any functions to check the angle of polygon?

I have 2 polygons that are connecting each other at a line like this. I want to remove overlaps between 2 polygons for which I see a function difference in JTS which works nicely but I want to apply ...
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5 votes
3 answers
270 views

Select polygons within polygons in same layer

I have a buildings layer that actually has a flaw. The inner courtyards, drawn as another polygon within the building polygon, should be islands of the building polygons. Instead, they are other ...
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Simplifying polygon product of erase tool results due to small gaps in erase features

I am using ArcGIS Pro 2.9 erase tools to erase overlaying polygons as such: with blue circles as input features and gray polygons as erase features. And here are my result: there are awkward lines ...
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1 vote
4 answers
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What is format for coordinates of polygon in KML?

I have a KML file with a polygon as shown below: <Polygon> <tessellate>1</tessellate> <outerBoundaryIs> <LinearRing> <coordinates> ...
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6 votes
1 answer
163 views

Selecting features that do not touch other features in same layer in QGIS

In QGIS I have a polygon layer where there are some isolated objects which do not touch other objects in the same layer. They are isolated and therefore I do not need them. How can I select these ones?...
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Resizing polygon in OpenLayers

How can I resize a Polygon? I want the user to enable enlarging a polygon by clicking on it, is there a native way to achieve that?
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7 votes
1 answer
379 views

MultiSurface Geometry type in QGIS: difference to MultiPolyon

Adding a new temporary scratch layer in QGIS, selecting the Geometry type, there are different options, between else MultiSurface. In the documentation, I could not find any information about this ...
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PostGIS - Area inside or outside w.r.t. a polygon

I need to check if a specific point belongs to the area defined by a polygon on a map using PostGIS. How can I specify if the area to be considered is either the one "inside" the polygon, or ...
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3 votes
1 answer
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Showing density of vector layer with polygons inside boundaries of another in QGIS

In QGIS I've got one layer showing local authority boundaries across the country (UK), and another which shows polygons of particular sites across the whole country. Can I show the density of the ...
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  • 33
4 votes
1 answer
137 views

QGIS: Dissolve adjacent small polygons

Does anybody know a solution for this qgis task? I have a polygon layer with many small and bigger polygons. I would like to merge/dissolve the polygons smaller than 100 m² with directly adjacent (...
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  • 309
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How to clip connecting datasets to each other in ArcGIS Pro

I have two datasets, one with administrative boundaries from one source, and coastlines from another source. I want to use both these sources to create a map, however the administrative boundaries are ...
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  • 127
2 votes
1 answer
45 views

How can you create a polygon in QGIS which covers a certain elevation range?

I am trying to isolate 3 different elevation ranges in QGIS (200-1200m, 1200-2200m, 2200-3200). I have made contour lines for each elevation but I want to make them into separate polygons so I can ...
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5 votes
3 answers
115 views

Measuring minimum distances for closest features between two polygon layers in QGIS

I am trying to find a way to measure minimum distance between two polygon layers in QGIS. I have one polygon layer (orange) which represents hunting areas, and one polygon layer (green) which ...
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39 views

Summing rasters in python with different shapes [duplicate]

I have a polygons shapefile with many individual overlapping polygons, each containing a unique value in the "Value" column. I want to iterate over each polygon in this shapefile (feature in ...
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51 views

Unable to write array to raster file using geocube in python

I have a polygons shapefile with many individual overlapping polygons, each containing a unique value in the "Value" column. I want to iterate over each polygon in this shapefile (feature in ...
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1 answer
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Clip tool does not update polygon areas in output in ArcGIS

In ArcGIS I created a buffer of 500m around a point. Then, I clipped a land use layer using the 500m buffer as the clip feature. The outcome is shown in the figure. My problem is that the layer ...
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Unable to rasterize polygons within for loop in Python

I have a shapefile with many polygons, with three separate attribute value columns as "colors": Blue, Red, and Green. For each color, I want to rasterize each individual polygon with that ...
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1 vote
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Get overlapping area between polygons by group rather than total area using the sf package in R?

I'm interested in calculating the area of overlap of different protected area types in a polygon I make of an animal's range using a Brownian Bridge. The shape files come from here https://www....
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2 votes
3 answers
351 views

Randomising colour for many of polygons in QGIS

Is there a way in QGIS to randomise the colour of all the polygons present in a single layer? I'm currently using QGIS 3.20.3 and a lot of the plugins for this that I've found online are not ...
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  • 79
3 votes
1 answer
132 views

Calculate the area (in %) for polygon categories?

I have a polygon and values of polygon is divided into four categories (showed in four colors in picture). Is it possible to calculate the area covered by each category. Like my values range from 0-5, ...
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  • 318
1 vote
1 answer
61 views

Calculate distance from centroid to border of polygon

I'm trying to measure the overall distribution of parks in a certain part of the city. For this, I have already retrieved a layer that consists of the park-polygons, and created a layer of hexagons, ...
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Creating polygons in ArcGIS Pro based on Survey123 (possibly automated with Notebooks?)

I am by no means a professional when it comes to using GIS. I am taking an elective in college, doing a project of my own choosing in GIS. This question relates to ArcGIS Pro, Survey123 and Notebooks. ...
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2 votes
1 answer
42 views

QGIS 3.8.3 - Create polygon with a specific width

I'm very new to GIS and QGIS. I'm trying to map areas of arable fields and would like to create a polygon that traces the edge of a field and is a specific width away from the edge of the field ie 8 ...
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  • 21
3 votes
1 answer
99 views

Creating arc with start, end, centre and radius using PyQGIS

I am trying to create some polygons where some of the sections correspond to curves/arcs. I have been provided with start point, end point, centre point, radius and direction (clockwise/ anti-...
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1 vote
1 answer
84 views

Clipping raster by polygon

I tried to clip a raster from processing toolbox, using Clip Raster by Polygons extent but I get the error message below. This map/raster was connected to an URL by using WMS/WMTS. Then the map was ...
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1 answer
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Creating circle polygons for 'Protection Zones' that are specific to individual points measured by radius in metres using QGIS

I have found similar questions to this but nothing that will work for my particular circumstance. I have points as a vector layer, I want to display their measured protection zones that are individual ...
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1 vote
0 answers
52 views

Taking min and max values out of certain polygons

I have taken out DEM data over a specific area and converted the raster to polygons. Now I want to code so I get the max value and the min value of "gridcode" of every set of polygons that ...
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  • 59
1 vote
1 answer
169 views

Assigning new values to a raster based on the mask layer in QGIS

In QGIS, I have two layers: raster and vector (green colored) of the same area of interest. Now, I want to assign "1" to the pixels which lie within the green region, and for the rest assign ...
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3 votes
1 answer
118 views

Identifying polygons with arcs using QGIS

I have a polygon layer where there may be polygons circular arcs as in the image. How can I identify the polygons which have those arcs parts?
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  • 1,383
1 vote
0 answers
32 views

Polygons at edges of orthographic projection

I am trying to make a globe type map with an orthogonal projection (made using a custom projection with the "origin" set to 20,0). The issue is polygons which meet the edge of projection are ...
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  • 11
2 votes
2 answers
168 views

Buffer around lines with varying width in between

My questions is about creating an elongated buffer around various lines and these buffers should run right in the middle of two parallel lines. The problem is that the lines do not have an equal width ...
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  • 343
2 votes
1 answer
103 views

Split polygon with West East direction with equal area in PostGIS

This code splits into NS direction but I need to split with WE direction (horizontally): WITH foo AS ( SELECT id,name,geom, blade FROM admin4 CROSS JOIN LATERAL ( SELECT ST_xMin(geom) + (ST_xMax(geom) ...
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3 votes
2 answers
295 views

Find and exclude polygons using GeoPandas

I have 3 dataframes: df1 (large polygons); df2 (small polygons, which overlays with large polygons) and df3 (points). How do I exclude large polygons in which points do not overlay with the small ...
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  • 521
0 votes
1 answer
290 views

How to delete polygon points in Google Earth web app?

I’m using Google Earth web app, because I can’t see how to create a publicly shareable link to a project created from a KML file and uploaded to Google Earth. When I draw a rough polygon, and then I ...
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  • 111
2 votes
1 answer
83 views

Add Polygon Feature in QGIS: polygon lines follow cursor when digitizing

I am drawing polygons in QGIS by moving the cursor and clicking to add polygon corners. So, four clicks, four corners to a polygon. All of a sudden, the polygon lines get drawn as I move the cursor, ...
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4 votes
3 answers
163 views

Creating difference of two polygon layers using Virtual layer in QGIS

I am trying to learn the usage of Virtual Layers in QGIS but I can't find a solution for a problem that seems very simple. I have two polygon layers and I want to have the difference. Polygon layer 1: ...
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6 votes
1 answer
102 views

Creating reverse of Inner glow when styling polygon in QGIS

In QGIS 3.22.1, the Inner Glow effects property (below) creates a sharp outer boundary that fades towards the inside. I would expect that the Outer Glow effects property (below) would provide the &...
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  • 7,069
4 votes
1 answer
138 views

Aggregating features values based on distance in QGIS

In a polygon dataset, I try to summarize values of surrounding features based on a minimum distance if their area is too small (e.g. 500 square meters). For example, I have 3 polygons with 300, 250 ...
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  • 1,444
0 votes
1 answer
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Changing the origins of SQL Server polygon geometry

I've got a table with polygon geometries, all with their origins @ (0,0). I want to recreate these polygons with the same dimensions, but at different origin points(x,y). Because all the original ...
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  • 33
2 votes
1 answer
145 views

Detecting polygon shape with PostGIS

I've got a polygon table with a UTM 10x10 km grid in a PostgreSQL/PostGIS database and I need to identify those cells that are not a regular square (i.e. changes in UTM numbers): Following the ...
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  • 2,315
1 vote
1 answer
224 views

GeoPandas Eliminate polygons (select by attribute)

I have a large GeoDataFrame with over 1 million polygons. Many of these polygons are of a small size and I want to merge them to one of the neighboring polygons (to the one with the greater area). I ...
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  • 85
5 votes
5 answers
316 views

Merging polygons only if three or more are on top of each other in QGIS

I am working on a layer with many polygons (circles). I would like to create a polygon containing only the areas where 3 or more circles overlap (in my example there would be only 1 area in the east). ...
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  • 51
0 votes
1 answer
48 views

Identifying outliers (not considering spatial relationship) in time-series data

The data I am working on is plant canopy cover (percentage within polygons (0-100%)) estimation from drones. This was collected over the course of 17 weeks. I was thinking on detecting outliers (not ...
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0 votes
2 answers
83 views

How to identify outliers (not considering spatial relationship) using ArcGIS Pro?

I am new to geospatial data and have a task to identify outliers from polygons. I have been looking at the different tools that ArcGIS Pro has to offer: Optimize Outlier Analysis, Optimize HotSpot ...
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0 votes
0 answers
76 views

CSV to shapefile

I converted a Shapefile into a CSV in order to do some calculations with the data and add some columns to the attribute table. I cannot seem to find out how to convert it to a geolocalized file again?...
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1 vote
0 answers
79 views

Trimming polygon based on its intersection with another polygon using shapely [closed]

I have two polygons intersecting with one another (x1 and x2). How can i trim x2 by the area it intersects with x1, such that x1 and x2 no longer overlap and x1 area/shape remains constant. from ...
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0 votes
1 answer
179 views

Unable to rasterize polygons with rasterio in python (ValueError: Sequences of multi-polygons are not valid arguments)

I am trying to take a polygons shapefile, loop through all the polygons/rows, and rasterize each one, where each raster file output rasterizes its associated polygon as if it were isolated (the only ...
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3 votes
1 answer
201 views

Using geocube in Python to rasterize each polygon in shapefile

I have a shapefile of polygons that I brought into Python in Jupyter Notebook via GeoPandas as a geodataframe. There are hundreds of polygons in this shapefile, and I want to create an individual ...
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1 vote
1 answer
127 views

Geopandas buffering successfully created buffers but deleted all attribute data

I am trying to use Python and GeoPandas to create variable distance buffers for a polygons shapefile I have. I brought this shapefile into python using GeoPandas. One of the columns of the ...
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3 votes
2 answers
131 views

Merging selected features based on multiple conditions using QGIS

In QGIS I'm working with a shapefile including polygons which represent the footprint of a building or parts of it (if parts have different heights). I would like to merge these parts but I have to ...
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