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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.

4
votes
2answers
38 views

Calculating line length within mulitple overlapping polygons using ArcGIS Desktop?

My question is similar to Calculating edge length of polygon within overlapping polygon using ArcGIS Desktop? However, my issue differs in that I have multiple overlapping polygons (upwards of 7) ...
5
votes
1answer
74 views

Prevent user from creating self intersected polygons

i'm working on a project in QGIS 3.4.1 Madeira. I want to prevent users from creating polygons with errors (like self intersection). When I digitize a polygon in QGIS i get a mark where the polygon ...
0
votes
0answers
17 views

Extract pixel number of Hansen lossyear map

I would like to extract the number of Hansen pixel for each different polygon of a shapefile. So if the polygon contains for example 10 pixel of Hansen I would like a column with this value. This is ...
1
vote
3answers
75 views

How to fill unconnected areas in polygon with the same attribute

I am trying to fill in the gaps with the same attribute. These arrowed areas belong to a city called 'Westbank', but the thing is, these areas are unconnected, how can I make a polygon out of areas ...
1
vote
1answer
29 views

Polygon to line (polyline) in R

I am looking for an easy way to convert a polygon to a polyline in r. I have tried this but dit not succeed: polygon <- readOGR("~path/", "polygon.shp") polyline <- as(polygon, "...
0
votes
1answer
56 views

How to batch geocode country names to polygons? [closed]

I have .xlsx dataset file with column "Country Name" and "Country Code" which have text records. I would like to geocode (assign) it to adequate country polygon in batch mode. The expected result ...
0
votes
1answer
41 views

Polyline length within corresponding polygon

ArcGIS Pro 2.3: I have a feature class of polylines and for each polyline I want to analyze against its corresponding polygon. The link is the FLIGHTID field and it is a 1-to-1 relationship. I am ...
2
votes
1answer
66 views

Split polygon by MultiLineString - shapely

I'm working on splitting a polygon given a set of linestrings using the shapely python library. The problem I'm facing is that a polygon cannot be split by a MultiLineString usingshapely.ops.split(...
3
votes
1answer
38 views

How might one optimise geospatial operations on complex polygons, especially plots in R?

Question: I'm attempting to run some simple plots on some shapefiles with a high number of complex polygons. These aren't massive files - for the example below, the shapefile is 70mb (15872 obs), but ...
3
votes
1answer
26 views

Make line along edge of several rasters

I'll try to keep this simple. Is there a way to make a polyline that runs along the edge of these polygons. It is cadastrals that assembly the coastline and I need to generate a line that works as ...
2
votes
2answers
72 views

Points to shapefile, with curved lines given center and radius (QGIS)

I'm a newbie in GIS and for a project I need to create a shapefile given some points in lat/lon. I have been following this tutorial: https://community.pyramidanalytics.com/t/q5tk8w/creating-a-...
1
vote
0answers
54 views

Shapely : cascaded_union seems to return too many polygons

I'm trying to get the union of around 4,000 polygons using Shapely's cascaded_union function. The output of this function is a multipolygon in my case, which is normal since many input polygons do not ...
0
votes
1answer
40 views

Exporting bounding area only via ArcGIS Pro?

I use ArcGIS Pro to export a layout as jpg format image. I just wonder if any tools in ArcGIS pro can help me export the polygon area only and remove or symbolize the rest area as grey? My quick ...
0
votes
0answers
12 views

Geospark - Creating LineStringRDD from coordinates extracted from the sides of each polygon in a PolygonRDD

I am using geospark 1.1.3 with scala and I am trying to split into lines a polygon shapefile dataset which contains 189 polygons. I am expecting to get each side of each polygon as a LineString, ...
0
votes
0answers
23 views

Missing raster data from masking with a spatial polygon layer in R

I am fairly new in R and I am trying to create a new raster by using a spatial polygon layer. I have the code written by using the mask function and the output is essentially what I want, but I'm ...
2
votes
1answer
30 views

QGIS coordinates lost creating polygons

New to QGIS, I'm facing the Problem that my lat, lon information has seemed to be lost creating polygons. I created layers importing csv files being gps points. From these points I used the function ...
0
votes
1answer
161 views

How to fix invalid polygon with self-intersection - Python [closed]

I have a self-intersecting polygon inside a shapefile. Does there exist a Python library which spots the self-intersections and makes it possible to correct them? I have found it is possible in QGIS ...
0
votes
1answer
64 views

How to find overlapping polygons of two shapefiles - Python [closed]

I have a mkl file A and a shapefile B containing polygons, each one of them having a single feature: the name associated to the polygon. I am looking for the polygons of A which are overlapped by ...
1
vote
0answers
47 views

Geofencing radius distribution/ratio across multiple geofences

I understand that this problem might be simple geometry, but Im using specific shapefiles for a geographical area and looking for a specific gis solution (hopefully code). Essentially Id like to find ...
0
votes
0answers
38 views

Merging Polygons to big polygon [duplicate]

I have a GeoJSON with many little polygons, I want to merge these polygons into one big polygon, I need the merged polygon to be a singular polygon and not a multipolygon. I tried merging the ...
0
votes
0answers
30 views

How to get the Lat/Lon coordinates if I am given a table of the MINxy and MAXxy, so that I can map it out in ArcMap?

Right now I have a table that looks a little like this: and I have the geographic coordinate system they were mapped in, but I need to display them as the polygons that they are in ArcMap.
1
vote
2answers
126 views

Create Polygon with Length, Width, and a center coordinate

Using Shapely or like library, How can I create a rectangular polygon with known Length, Width (in meters)(Drawing over EPSG: 3857), and center coordinates (EPSG: 4326)? The output needs to be in ...
3
votes
3answers
88 views

Merging several polygons located at same place in same layer using QGIS?

This is my problem that I first present using a Screenshot: In a layer, I have many cases of figures like this one: Polygons that overlap in the same place. Each of its polygons represents different ...
-1
votes
1answer
45 views

Finding polygons that overlap other polygons within same layer using ArcPy? [duplicate]

I have a shapefile containing polygons. I would like to select all polygons within the layer that overlap with other polygons within the same layer. The closest I have gotten is the Intersect tool ...
1
vote
1answer
52 views

In OpenLayers how do I prevent linestrings and polygons disappearing as I zoom out?

I can see how to do this using a feature style function with 2 styles (similar to the Custom Polygon Styles example). One would be the normal linestring/polygon one and used at high enough zooms. The ...
1
vote
1answer
61 views

Shapefile layer not showing in QGIS [closed]

I have a polygon layer which is listed at the top of the layers panel, however it is showing underneath other layers on the map canvas. It is in the right location but despite being at the top of the ...
1
vote
1answer
65 views

How to replicate a polygon over several points with different locations in Arcgis? [closed]

I have two shapefiles, one is a polygon and the other is points. I would like to create a new shapefile which has the shape of the polygon in all the places that there is points. I would like to ...
0
votes
1answer
66 views

Points that fall outside a polygon in QGIS [duplicate]

I need to figure out how many points, and which ones (with labels) fall outside the boundary of a particular polygon in QGIS.
1
vote
0answers
29 views

Repairing gaps in polyline to polygonize

I have a large, complex coastal outline (polyline) that I am trying to polygonize. It won't work so I suspect there is a gap somewhere or some other error. Any ideas on a workflow to repair the ...
1
vote
0answers
20 views

Polygon Clip While mainting Ratio Policy

In my project, I am using drivetime polygons to clip block group data to get the population in that drive time. The drive time shapefile I am testing on has 5 polygons. I want to update the population ...
1
vote
1answer
67 views

Rotating polygons by value from attribute table using ArcPy?

I have 60 polygons saved in one shp file. Is there a way to rotate them by the angle value stored in the attribute table? I know how to do it manually; I am looking for more automated way (Every ...
1
vote
0answers
37 views

Converting Land Cover Vector to Raster?

I have a question regarding converting a vector forest cover layer to a raster layer. The basis of what I am trying to do is determine what percent of forest cover is within a set of 1x1 km grid ...
2
votes
1answer
50 views

How to connect polygons to make a circle?

I created polygons from a raster on which I ran an edge detection filter. I turned the edges into a polygon layer (multipart splitted into single parts). The intention was to have circular polygons at ...
1
vote
1answer
57 views

Polygons are unable to be edited and have no feature, although they are listed in attribute table with three features

I found that several lakes in the GRanD database (global reservoirs and dams) are unable to be selected for editing like normal polygons, and they have no feature at all, although they are shown in ...
0
votes
1answer
24 views

GeoServer - WMS v WFS (polygon label issue)

I am hoping that when I switch over to WFS that my multi-polygon labelling issue will disappear. Currently I am using WMS, and I believe the reason I am seeing multiple labels within my polygons is ...
0
votes
1answer
35 views

ST_Contains always return false

I'm definitely a 'geonewbie' and I'm trying to test if a point is contained inside a region. I have taken some certified data here: https://www.istat.it/it/archivio/124086 getting WGS84 UTM32N for ...
0
votes
0answers
23 views

Forming rectangle between two diagonal points using MySQL?

I've been working with Google Maps a bit lately and they provide a set of bounds (two points, northeast and southwest). ex. "bounds": { "northeast": { "lat": 34.111236 "lng": -118.2840872 ...
2
votes
2answers
58 views

Tool in QGIS to construct polygons based on network of lines

Is there a tool in QGIS similar to "Contruct polygons" in ArcGIS that creates polygons from existing lines? This is different from convert lines to polygons that requires closed loops (minimum of ...
3
votes
0answers
46 views

Unable to compute intersection between two polygons using PyQGIS?

I have two polygons in different layers. I am trying to find the intersect between the two polygons. Below a figure showing my test case. I initially wanted to find the intersect between the green ...
3
votes
2answers
222 views

Creating polygon from hole in QGIS?

I work with this polygon and try to find a way to create a new polygon from the empty gap (not distinguish it) in the middle of the polygon. I succeed to do it with a "difference" tool- but used with ...
0
votes
1answer
26 views

How to free the memory of return value of OGRGeometry::Buffer()?

I have in C++ (gdal 2.3.2) OGRPolygon poly; OGRGeometry* geom = poly.Buffer(1e-12, 1); now how do I free the memory allocated for geom after done using it?
0
votes
1answer
60 views

Using centroid point to generate polygon using ArcPy? [closed]

Is this possible to generate polygons from points (which are centroids of future polygon)? I got shapefile with ~250 points + they have got two attributes: length and width. I don't need complete ...
1
vote
1answer
37 views

Two adjoining lines becomes clearer than two individual

When having an outline style where the two edges interfere, they become much more dense in the color than when they are individual, see image below. It is an outline of a polygon. The thing is that ...
2
votes
1answer
50 views

Expanding Polygon by distance using PostGIS?

I am trying to expand a polygon in a particular manner with PostGIS. I need a new geometry that is a bit like a Buffer, except Buffer produces rounded corners (lots of vertices) when using it on a ...
0
votes
1answer
74 views

Lines in Polygon Analysis

This question is similar to the "points in polygon" analysis, but I want to keep the attribute data for multiple lines within a single polygon. The data source is multiple line segments representing ...
1
vote
0answers
31 views

R Clip Simple Features Multiple Polygons with a Polygon (or another multi-polygon)

I have two polygon layers, a set of aquifer polygons and a set of district boundaries. I'm trying to clip the aquifer layers to be in only the districts that I want. From examining the other posts ...
2
votes
1answer
34 views

Distance from edge of each polygon to nearest point, such that points within each polygon aren't included

Using ArcGIS 10.5, I have a cluster of polygons that represent districts (together this cluster of polygons creates a nation). I also have thousands of points that represent offices. I would like to ...
2
votes
1answer
61 views

Cleaning topology errors in PostgreSQL (vector data) using QGIS?

I need to append the shapefiles to a PostgreSQL database. Once the data gets appended to PostgreSQL, some topology errors like gaps & overlaps can be seen. By using the v.clean tools the topology ...
2
votes
0answers
34 views

Graduated color display of overlapping polygons in ArcMap

Is there a way to display overlapping polygons in a graduated color symbology based on the level of overlap within the same feature layer? For example, in one area of the map there are two polygons ...
0
votes
0answers
38 views

Erroneous contour polygons in QGIS 3

I have a global DEM and try to calculate contour polygons for 4 different heights in QGIS. In the first image below, you can see the colored DEM (white = lowest; yellow = higher; orange = highest) as ...