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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.

2
votes
1answer
260 views

How to calculate mean value of a raster for each polygon in a shapefile

I wrote a Python script who calculate, for rasters, mean value for each polygon of a shapefile. But I think that it's a "war machine" (it takes many treatment time) and I would like to simplify it. ...
1
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0answers
135 views

Attributing polygons based on line attributes

I'm using QGIS 2.18. I have a grid that I need to calculate Azimuth and length for each side. Most have 4 sides but some ( see Gird C below) many more , up to 12. My process now convert Polygon to ...
1
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2answers
53 views

Find the NW vertex of a rotated polygon

I am using QGIS 2.18 and I am wondering how to find the NW corner of a polygon and create an attribute of that point number. See the attached image. For example, please node 8 is the NW corner for ...
1
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0answers
113 views

r - intersection of 3D objects

How can an intersection of 3D object with 3D object be done in R, for example a 3D line with 3D polygon ? Saw that "sf" provides some possibilities but didn't get the desired result. What was ...
1
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0answers
132 views

How to fix self intersected polygons visually, as well in QGIS?

I have same invalid polygon features because of self intersection. I can make them valid by using fix geometries tool in QGIS 3.2. However I want to show them valid visually also. The feature is valid ...
4
votes
1answer
272 views

Fitting known size polygons into irregular polygons using ArcGIS Desktop?

I have a task that sounds simple, but I just can't get through the last step. I need to find suitable areas where wind farms that have a size of 500x150 meters, could be placed. The restrictions are ...
3
votes
1answer
89 views

Determining validity of odd polygon using ArcObjects?

Using ArcGIS 10.4.1 a user in our department created a polygon and saved it to a feature class as shown below. The area covered is correct as at times it could overlap itself. I have calculated the ...
2
votes
2answers
308 views

Leaflet popup disappear or moved over drawn polygon

If I would like to popup something over an actually drawn polygon, then it sometimes disappear or moved to the first point of the polygon. https://jsfiddle.net/o149mgwj/19/ var drawnItems = new L....
0
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1answer
87 views

Find the intersecting polygons between 2 tags in OpenStreetMap using Overpass API?

I need to find in Italy all the intersecting polygons of: all airport terminals of the tag["aeroway"="terminal"] that are inside only international airports of the tag["aerodrome"="international"] I ...
1
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0answers
32 views

Automatic slice of polygon

I have a data source, that sometimes returns geometries which are not properly cleaned e.g. the pink polygon is only 0.02 cm wide and is always on the edge of the whole geometry which consists of the ...
1
vote
1answer
47 views

Osm2pgsql - Lines instead of polygons that represent buildings

So I am using a PostgreSQL database with the PostGIS extension to extract building data with addresses from osm data. I just discovered that in my dataset, imported with osm2pgsql of the german city ...
1
vote
1answer
74 views

Get pixel values from a raster using a multipartpolygon

I'm trying to get the mean value of pixels from an NDVI raster, that intersect the geometry of a FeatureCollection, that is a multipart polygon which represents my sample area, but I can't find the ...
1
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0answers
37 views

Find points from list that satisfy particular rule AND are within a shape/polygon

I have a list of points which I have plotted using rule-based symbology as 4 categories. I want to produce (and export) a list of the points that satisfy a certain rule (e.g. "pUXO" = 'Y') AND lie ...
1
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0answers
86 views

Dealing with a hole (or inner ring) at the intersection of two MultiPolygon polygons in Python Shapely

I have a problem with Shapely geometry object MultiPolygon (the exact data is shown below) in Python. I need to find a way to merge the small grid cell polygon with the larger polygon but after ...
8
votes
1answer
143 views

The longest straight line (L) within a polygon and the longest perpendicular line (T) to L

I'm mapping elongated glaciological features within QGIS 2.18.22 and I need to measure the longest straight line (L) and the longest perpendicular line (T) to L (as illustrated in the picture) within ...
0
votes
1answer
235 views

Draw polygon on load not working - OpenLayers

The following code should have 3 features: Draw a polygon on load On draw end send coordinates On modify end send coordinates 2&3 work as expected. I added the drawn polygon last, there is no ...
4
votes
1answer
275 views

Turning vector grid into individual shapefiles using QGIS?

I am using QGIS and I created a vector grid on a crop field in order to cut it into plots. I want to save each grid cell into individual polygon shapefiles automatically. Here is an example of a ...
0
votes
1answer
48 views

Intersecting polygons from different layers based on common values using ArcPy? [closed]

I have two polygon shapefiles (ShapeA and ShapeB) that share some areas. The shapefiles have one attribute in common (CODE) and I would like to do a selection, where I select all the polygons in one ...
1
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0answers
262 views

Generating a single geohash for a bounding box in python

the following code generates bounding box for the coordinates that are given in the input but currently it generates geohashes for all the 4 coordinates of the polygon. i want to be able to generate a ...
1
vote
1answer
164 views

Disappearing polygons when zooming in QGIS 3.0

I am using QGIS 3.0 and loaded a polygon layer from a shapefile containing more than 300,000 polygons. When zooming in some polygons are not drawn (not the entire layer).
1
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1answer
524 views

Setting cell size on “Polygon to Raster” tool, in ArcGIS?

How do I properly set the cell size that I want when converting polygons to raster files? Also on the raster file Layer Properties what exactly does the Cell Size indicate, as it doesn't seem to ...
1
vote
1answer
59 views

Selecting all polygons along northern edge of shapefile in R

I have a shapefile of Mexico composed of Admin 2 polygons. I am trying to create a buffer along the Mexico-US border, in R considering this is a shapefile of Mexico only and I want to retain the ...
1
vote
1answer
51 views

Error in executing clip with polygon from another layer

I have used clip with polygon from another layer with the Digitizing tools toolbar successfully before but I am running into an error recently. I have selected one polygon in the layer to clip and ...
1
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0answers
36 views

arcpy.Project_management is projecting points but not polygons? [closed]

In my current project, I am grabbing data from a web service and want to change the projection before inserting into a production db. For some reason when I am projecting the data, some of it is being ...
0
votes
1answer
39 views

Identifying the greatest value point within each polygon

I have a series of polygons (4,000) and a series of points that exist on the perimeter of each polygon (3 to 5). The points refer to the elevation value which has previously been extracted from a DEM ...
6
votes
1answer
176 views

Constrained Voronoi polygons QGIS

I have a shapefile of polygons, which are effectively borders of a geographic unit (consider as an example the 50 u.s. states, each state has within it some number of points.). I'd like to create ...
3
votes
2answers
147 views

Line/Polygon intersection with a tolerance in QGIS

I have a layer with Polygon and a layer with Polylines. I am looking for the list of Polygons crossed by the Polylines. Just here it's relatively simple: intersection function. That said, the ...
2
votes
1answer
174 views

Use QGIS or QField with a GPS physically walk a polygon in the field

Is it possible to use QGIS or QField with a GPS to physically walk a polygon in the field? I'd like to use the software to physically walk shapes in the field but have been unable to find information ...
3
votes
1answer
112 views

Sorting features in legend

I have a map with a polygon layer containing 100+ features. I want them to display on the legend and the Layer Tree using the Polygon's ID and then its name i.e: "Id - Name". I'm using the ...
3
votes
3answers
493 views

Converting CSV (polygon coordinates) to polygon feature class (shapefile)?

I have a CSV table as following : ID;POLYGON 1;(-7.59443,33.55933):(-7.59416,33.55937):(-7.59414,33.55922) 2;(-7.58361,33.56655):(-7.58148,33.56655):(-7.58148,33.56486):(-7.58361,33.56486) The ...
2
votes
1answer
52 views

Drawn polygons in QGIS (3.2) are not accurate in ArcGIS Online?

I am drawing polygons in QGIS (see figure 1), but when I import the shapefile to ArcGIS Online, it does not look like what it is on QGIS (see figure 2). Instead of being an intricate polygon, its all ...
0
votes
1answer
94 views

Extracting vertices in line segments using ArcGIS Desktop? [closed]

I have ArcGIS Desktop 10.6 and have many polyline features and want to be able to extract the vertices of each line segment that looks like this: I want to keep the line ID associated and be able to ...
2
votes
1answer
4k views

Create a polygon from coordinates in GeoPandas with Python

I was trying to create a simple Polygon from a list of coordinates and export it to multiple formats (including shapefile and GeoJSON) and wanted to automate it using Python. There were some good ...
0
votes
1answer
35 views

Cutting rasters using polygon and obtaining pixel specific data using ArcMap

I have a georeferenced polygon file that I want to use to cut several different raster files. I am looking to analyse the individual pixels within those cut areas. One of the raster files has a ...
3
votes
1answer
124 views

How to plot a point on the highest elevation of a raster on a polygon. QGIS

I have a shp with more than 1700 polygons on a elevation raster. I need to plot a point that represents the highest altitude location within the polygons, and then export those points as a new shp.
1
vote
0answers
49 views

Removing dateline in polygons

I am using the marine boundaries data from MarineRegions.org and I'm trying to use cylindrical equal area with a -160 central meridian. I successfully removed the dateline from polygons basically ...
0
votes
0answers
34 views

Arcgis Pro's Eliminate not eliminating selected polygons?

I'm trying to use Eliminate to reduce the number of polygons in my dataset that have a very small area size. As far as i understand the tool, you have to first create a selection in the dataset, and ...
3
votes
1answer
446 views

Filling gaps between polygons using QGIS?

Here are my polygons of town blocks. The colored towns are considered as areas where they have the same post code. What I eventually want is to make seamless polygons where there are no gaps between ...
0
votes
1answer
378 views

Why does mysql ST_WITHIN work for some MultiPolygons but doesn't for others?

The mysql queries are to return all POI's within a certain country. This works (for Angola): SELECT poi.poi_id, poi.poi_address_full FROM poi WHERE ST_WITHIN( poi....
1
vote
1answer
32 views

QGIS Union erroneously creating gaps

I'm trying to do a union between two Polygon Shapefiles, but when I do Vector > Geoprocessing Tools > Union I have the odd issue where most of it works fine, but some areas are returned in the union ...
1
vote
1answer
55 views

Generating centerline for polygon using ArcGIS Desktop?

How could I generate a nominal centreline for a polygon and then generate lines perpendicular to this centreline at regular intervals? I've explored generating a centreline using the tools here: http:...
1
vote
1answer
74 views

Decrease polygon vertices count maintaining its aspect

Is there an algorithm or technique that allow me to decrease the number of vertices of a polygon while maintaining it at some acceptable aspect? The problem: I have a functionality in my system (...
0
votes
2answers
56 views

Calculating width of polygon relative to polyline using ArcGIS Desktop?

I need to estimate the different widths of the polygons that surround some polylines. The polygons correspond to wetlands (buffer zones) and the lines represent the rivers. The catchment that I´m ...
2
votes
2answers
187 views

How to polygonise a large and detailed raster into a single valid polygon with QGIS?

I am doing research on the protected areas of the Amazon rainforest and I need to create a single polygon layer that has all the forested non-protected areas in one attribute row. I have tried using ...
0
votes
0answers
10 views

Polygon Multiple FID attribute for one

I am using ArcMap attempting to find the total area of this multi-part polygon, however in the attribute table there are multiple FID corresponding to the same polygon. They all have the same acreage ...
2
votes
1answer
43 views

Merge/Dissolve Polygon overlapping within

I have a polygon that has been broken down to an intersecting analysis point. Each segment has its own acreage within an acre field on the attribute table. I want the intersecting lines to be removed ...
0
votes
1answer
84 views

GDAL ogr2ogr OracleSpatial to Shape: Multipolygons with wholes/multiparts are missing

We're holding geodata in an Orcale database (11g) with spatial extension. I want to unload specific polygons and convert them into Shape for further local processing. The table where I'm unloading ...
0
votes
1answer
422 views

Getting attribute from overlapping feature from other polygon data using ArcGIS Desktop?

How do I transfer attribute data from one polygon layer (A) to another (B)? I am using ArcMap 10.2. I tried using Identity. It doesn't work. I also tried converting (A) to point so it has the same ...
0
votes
0answers
25 views

Polygon interpolation neighbour average?

I am trying to estimate empty values based on a polygon layer we received from another study. Is there a way to calculate an average value for polygon A based on neighbours B,C, etc that border it? I ...
1
vote
1answer
61 views

Change attribute of a line according to overlapping polygon features

I'm pretty new to QGIS and python in general. For my work I'm faced with a bit of a problem. I got 100-m-segments of several streams and polygon-features of the surrounding substrate. The polygon ...