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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.

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0answers
38 views

Finding overlapping geometries in the same table using PostGIS [on hold]

I have a table containing about 50,000 polygons and some of them are overlapping. I'm trying to use PostGIS to return a table with all the overlapping parts of the polygons along with some of the ...
0
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1answer
29 views

How can I calculate the direction of a Google Maps polygon?

To create a hole in a polygon, you need to know if the inner polygon is in the opposite direction as the outer polygon (See here). How can I calculate this? Here are some examples: var ...
2
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2answers
36 views

QGIS how to sum a certain vector field inside a polygon and populate a field in the polygon?

I have a polygon with vector point civic addresses inside it. Each civic address has a different number residence. I want to sum the total number of residence inside that polygon and it populate a ...
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1answer
25 views

Calculate the total area from two intersected polylines

If two polylines intersect with each other and there are more than 2 intersect points, there is more than 1 closed area will be created. How can I get these areas as polygons in ArcGIS?
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3answers
81 views

Creating polygons that share the boundaries of existing polygons

I'm creating polygon (that about actual vegetation). First, I create one polygon After that, I will create more polygons that share the boundaries of existing polygon. But, it show result like below ...
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0answers
15 views

How to extract data from raster data set? [closed]

I am looking to create a standalone QGIS python application that can allow the user to enter in a coordinate on the US and find the population in a circle around this point and display the circle on ...
2
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1answer
56 views

Using ST_UNION to combine several polygons to one MULTIPOLYGON using PostGIS?

I have a problem with ST_UNION So, I have a several polygons DB looks like this I need UNION all off those polygons to one multipolygon and get result that looks like this I tried use ST_UNION ...
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1answer
15 views

Using raster::rasterize's getcover to get total polygon area with overlaps

I want to use rasterize to get how much of a raster cell is covered by polygons. This can be done like this: library(raster) p1 <- rbind(c(-180,-20), c(-140,55), c(10, 0), c(-140,-60), c(-180,-20)...
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1answer
37 views

Moving point labels on vertices inside of polygon

What I'm trying to do is to label vertices of a polygon with a number and plot that number inside the polygon. So far I extracted the vertices to a 2nd point layer. Named them correctly and plotted ...
0
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2answers
60 views

QGIS Hex grid with the shape of vector

I'm trying to make a hex grid net with the shape of polygon. Unfortunately, the grid net is in the rectangle shape (see the screenshot). Any advice how to do it?
2
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2answers
33 views

Unite several polygons that share boundaries in QGIS

My study zone is in the middle of two geologic maps with two different shp files. Is it possible to remove the boundaries of the polygons between these two maps that are created at the union of ...
0
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3answers
71 views

Removing 180th meridian line on map of Russia?

I'm not sure how to remove the line that represents the 180th meridian (international dateline) on my polygon. I have the "Russia Country Boundary 2017" feature layer added from the Living Atlas. My ...
1
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1answer
24 views

Rasterize the full area of a polygon, not only midpoints, using R [duplicate]

The default function in raster::rasterize is to see if a point is within a polygon and if yes, make a cell. This results in that some of the outer parts of the polygon is not covered by the new raster....
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2answers
23 views

Java GeoTools API: getInteriorPoint does not work on an intersection between Polygon and MultiLineString

I'm working on a Java project using GeoTools API that want to get the interior point getInteriorPoint(), from the geometry coming from an intersection between a Polygon and a MultiLineString. Please ...
5
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0answers
58 views

Clipping rasters to mask layer QGIS 2.18, 3.4, 3.6 not working

Having a problem clipping a singleband GEOTIFF of Canadian land uses to a vector Quebec provincial boundary. When I do Raster -> Extraction -> Clip by mask layer, the program processes endlessly. I ...
0
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1answer
21 views

Convert Oracle data to polygons using R

I have a polygon file, taken from an Oracle database, that looks something like this: ID FMC_AREA_TYPE_NAME DESCRIPTION 1 162 HARBOUR Esbjerg 2 164 HARBOUR Thyborøn ...
1
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0answers
30 views

Calculating distance between point and MultiPolygon Geoseries object in Python [on hold]

I want to calculate the distance of a point from the Multiploygon geoseries object created using cascaded_union function of GeoPandas. Following is my code: import numpy as np import pandas as pd ...
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0answers
33 views

Extract point data to polygon features [duplicate]

I am trying to import data from a point that lies on a certain polygon feature (or raster). As an output I would like the polygon feature to have the point data as a new field in the attribute table. ...
2
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2answers
68 views

Measuring length of edge of polygon

I have a layer of polygons, cadastrals, that i'd like to have the length of the edge of: I thought about doing this: Dissolve the polygons Create one large dissolved polygon Making a; From polygon ...
1
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2answers
33 views

Creating an arc with set angle and range using QGIS?

I'm currently using QGIS 3.6. For a while now to map the arcs of fire for historical fixed weapon emplacements. Creating an arc to a set range to a set angle is extremely important for my analysis ...
2
votes
1answer
49 views

Identifying Parcels on Street Junction in QGIS

I have the following shapefiles (click here to download them): parcels polygon parcels point streets/row polygon streets line I use QGIS to manually identify polygon parcels with street corners (...
1
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0answers
29 views

Calculating the area of raster within polygon

I have a raster layer with values of energy demand in each cell. I would like to know the area of the raster within each polygon (see screenshot). Any suggestions on a simple approach for this?
2
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1answer
28 views

Make polygon appear as point when zooming out beyond set range in ArcGIS Online

Is it possible to have a polygon layer visually appear as a point when zooming out beyond a certain extent that i will determine in a web map in ArcGIS Online? Or do i have to add a different layer ...
2
votes
1answer
46 views

PostGIS - unique constraint for spatial equality

I have a polygon column for which I would like to add a unique constraint that tests for spatial equality akin to ST_Equals so that it ignores vertex order. For instance, I would like these polygons ...
1
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1answer
77 views

Inherited values between polygons in QGIS? [duplicate]

In this project, I have three polygons, see the image below "Polygons_From", includes input attributes, i.g. "Value_1", "Value_2", "Value_3", and $area for each quadrate (on the image there are two ...
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0answers
72 views

Drawing longest polyline within polygon? [closed]

I am looking for a GIS tool/script (preference on QGIS but I can also use ArcGIS/Matlab) that allows creating a polyline layer from a polygon layer where a polyline is drawn for each polygon. The ...
0
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1answer
46 views

Merge small underlying polygons into overlaying shapefile with larger polygons [closed]

I have a dataset with the average rent prices saved in a vector layer (.shp). It is "street" based, so it has quite a fine resolution. I have a different dataset (containing info about crime rates) in ...
1
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1answer
42 views

How to auto populate feature attribute values for new polygon (B) from parent layer (A) where B is made over layer A?

Is there any way in QGIS where we can auto populate new layer feature_attributes from parent layer? We have layer A as . It has attributes including: f_id, class_name, class_type, r_total. We now ...
3
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0answers
31 views

Creating equidistant sampling points in polygon in QGIS 3.6.0?

I have figured out how to add random points inside polygon boundaries. Although this works well, nevertheless I need a few different things to happen for my application. What I would like to do is ...
0
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0answers
20 views

Creating a grid of modifiable hexagonal tiles as overlay in geopandas

I have geo-tagged car sharing dataset which I am analyzing using geopandas. For analysis purposes I would like to create my own polygon overlay of hexagonal tiles. I have managed to find a ...
1
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0answers
28 views

How to remove complicated shapes in ArcGIS - generalization [duplicate]

What can be the way of simplifying polygons in ArcMap? I have a shapefile with buildings and I have to make them as simple as it's possible. I used already some tools, like: dissolve, union, ...
1
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1answer
44 views

Python - Convert shapefile lat-long value from Degree minutes seconds to Degree decimal

I am processing shapefiles in python using standard library functions like Python “shapefile” library and GeoPandas. I have two shapefiles having the same projected co-ordinate system-> ...
0
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0answers
18 views

Identify raster cells with point shapefile in QGIS

I have a binary raster, a point layer, and a polygon grid layer. I want to know how many raster cells have a point associated with them within each of the polygons of the grid, and the value of each ...
3
votes
3answers
208 views

Prioritising polygons in QGIS

I just created a layer in which I hand drew a lot of polygons. Now I want to fill out the Attribute table through commands since it will save me a bunch of time. Therefore, I calculated the area of ...
0
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0answers
30 views

Editing polygon layer and snapping to another layer using ArcMap?

I'm using ArcMap, and i've got two large polygon layers that are of the same area (Canada). One layer is made up of 2,500 polygons, the other is 14. when I clip (using one of the 14 layers) I will ...
0
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1answer
37 views

Polygon Neighbors for boundary polygons

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 ...
0
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1answer
31 views

Check if a VERTEX of one polygon falls anywhere within the boundary of another polygon (in Python)

This is different than simply containing, overlapping, etc. For example, imagine a circle partially overlapping a square: The circle and square both overlap each other, both intersect each other, but ...
1
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0answers
17 views

Counting points in a scratch layer poygon

I'm using QGIS 3 I am trying to count the points in a scratch layer polygon. when I use the count points in a polygon tool it says there are no points in my polygon which is untrue. I figured the ...
5
votes
1answer
111 views

PostGIS function to move a polygon to centre over new point coordinates

Background: (Note: I am trying to do as much of this as possible in PostGIS/PostgreSQL) I have a PostgreSQL table containing location data of an aircraft in orbit around a city. Every second a new ...
0
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1answer
33 views

Transforming polygon from Arc 1960 UTM Zone 37S to WGS 1984 UTM Zone 37S?

I have a polygon which is in Arc 1960 UTM Zone 37S coordinate system and I need to transform it to to WGS 1984 UTM Zone 37S. I have not been successful in doing this using ArcMap. Is there a ...
4
votes
1answer
124 views

Distortion of City -Boundary-Polygons proportional to population size in QGIS?

Is there a way to distort the size of polygons proportional to their population size (as in column in the attribute table)? I want to create a map that looks similar to this: the cartogram2 plugin ...
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0answers
37 views

Creating and combining polygons in R with sf

I'm getting a bit confused by a few supposedly basic tasks involving polygons in R. I'm tying to keep everything in sf, but if I need to switch to sp that's ok. Firstly, I'm creating some polygons ...
3
votes
1answer
57 views

Moving Multiple Points Into Single Polygon using ArcGIS Desktop?

I have several days worth of geotagged imagery to which I've attached a tree canopy mortality rating. The goal is to eventually join all of these classifications to a shapefile that contains ...
2
votes
1answer
57 views

How to create a polygon from a data CSV file with coordinates using QGIS? [duplicate]

Having the following information in a CSV file: I want to build a polygon with all the points where the Group name is the same. For example I want to join all the points where the group is T101 and ...
0
votes
0answers
20 views

NHGIS census files get lat/lon from polygon

I've never worked with shapefiles before and I'm having a lot of trouble with something that I think should be pretty simple. So I have the census tract files from NHGIS for 1980 and the structure ...
0
votes
1answer
67 views

Counting number of polygons within polygons using R?

I have two huge shapefiles. One contains polygons of one kind of vegetation and the other one representing a grid. A situation as follows but, of course, much bigger: I need: the efficient way to ...
0
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0answers
13 views

LSIB feature does not align with island boundary

It looks like there is an alignment issue that arises in EarthEngine with the LSIB polygons. It exists for Greenland in both the Detailed LSIB 2013 and Simple LSIB 2017 datasets, and can be verified ...
2
votes
1answer
52 views

Getting the percentage area of intersecting polygons [closed]

I have the polygons for census tracts within New York City. I also have the polygons for the parks. What I would like is % of the census tract area, with an added 400 meter buffer, that is park. I'm ...
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0answers
24 views

How to compare centrality of points in different shaped and sized polygons

Suppose I have several polygons of varying shape and size, each containing a single point. I want to compare the centrality of each point, and determine which point is more central to its polygon. I'm ...
0
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1answer
31 views

Select Features outside of polygon or reverse .filterBounds Google Earth Engine

Is there an easy way of selecting only those features not contained inside a certain polygon, let´s call it aoi? FeatureCollection.filterBounds(aoi) retrieves every Feature inside aoi?