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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22 views

Querying Esri WMS based on Polygon

I have an Esri WMS server serving raster data. I can query this using openlayers TileWMS, all appears beautifully on my basemap. I need to be able to query the WMS based on a polygon and display my ...
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12 views

Match small polygons that are within a bigger polygon to collectively have the geometry of the bigger one

I have two layers: The green polygons (with detailed information on inhabitants in the attribute table) and the blue ones with blue boundary, which are housing blocks (with the shape needed). The red ...
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1answer
54 views

Calculating polygon attribute based on intersection with grid in QGIS

I'm trying to use QGIS to profiling polygons in a layer. There is also another grid layer, each grid contains its own demographics information. Assume the demographics are evenly distributed within ...
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31 views

PostGIS add polygon in meters around a point (lat,long)

I have a point in my PostGIS database that is put in using the lat/long using srid: 4326. The point represents a car driving, now I want to add a polygon of the cars shape around this point and update....
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Empty result while running Processing Modeler

There is one polygon layer, see image below I am simply trying to achieve all the holes as polygons with the following step-by-step algorithm Dissolve all Delete holes in the output of 1 Difference ...
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24 views

Make a draw object option in Leaflet and that stores it in the webmap in a database or on a server

I would like to set up a simple web map which should be used as an information for those out in the field that needs to show something immediately. So I would just load the web map and get an overview....
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19 views

Splitting polygon by sections obtained from IDW interpolation

I used IDW to show the rainfall pattern over a region ... the attached picture show the result ... my area split into three ranges that show 3 different colors... How can I split one original polygon ...
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27 views

Converting multipolygons to polygons in Leaflet or Python [closed]

Given a multipolygon like the state of Hawaii, how can I generate the polygon that most tightly fits all the islands. I think this may be what is referred to as the "Minimum Area Circumscribing ...
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1answer
43 views

Automatic filling of rings with additional polygons in QGIS

I have a large layer with a couple of thousand polygons mapping inland waterbodies. A lot of these contain rings, mapping islands. I would like to count the number of islands and do some statistics ...
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1answer
25 views

US Census Bureau Shapefiles with district IDs

I am loading senate district polygon shapefiles from https://www.census.gov/cgi-bin/geo/shapefiles/index.php?year=2019&layergroup=State+Legislative+Districts into my Leaflet map. Well, to be ...
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62 views

Polygon poıints to simple GPS [closed]

I have nothing to do with codes and geography unfortunately and I need to find some places given in polygon points. It has been written something like POLYGON 1 To right Y 470333 to up X 4358838 How ...
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Adding multiple vertices in QGIS

I created a new polygon feature in QGIS 3.4 using the add polygon feature tool. I accidentally clicked the right mouse button to finish creating the feature. I want to continue being able to add ...
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44 views

Is it possible to automatically snap polygons in the same layer in QGIS?

there are similar questions but I still couldn't figure out if it's possible to do this in QGIS. I have a layer with categorized point data (3 categories), I use minimum bounding box/convex hull in ...
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1answer
23 views

Adding hyperlink in a popup which comes from a polygon?

I need to add a hyperlink in a popup which comes from a polygon. The following piece of script shows the text which needs to be a link. var polygon = L.polygon([ [51.569, -4.144], [51.568, -4.145], [...
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2answers
84 views

Convert shapefile into usable data

I am new to GIS data. Our organization uses ArcGIS to map parcels of land used for agriculture. The lowest addressable level is currently a single polygon, representing a parcel. Throughout the year, ...
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43 views

Import polygon to Google Earth Engine Python API script [closed]

Is it possible to import shapefiles into Earth Engine Python API scripts directly from by computer, as opposed to first uploading them as Earth Engine assets? For examples, I'm thinking maybe there ...
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1answer
44 views

US Census block boundaries shapefile [closed]

I am searching for a single file of all roughly 11 million US census blocks. Where can I find this?
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2answers
306 views

Saving shp polygon from Google Earth

I have made a polygon in Google Earth, but somehow there is no icon or feature for saving .shp. Is there any way to save a shapefile in Google Earth?
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39 views

Auto-generate Grid Reference for Point and Polygon features within existing Shapefile, QGIS

I have various point and polygon layers (shapefiles) which I use regularly in QGIS (3.6.3), and often need to work out their location as an 8 figure grid reference (British co-ordinates, EPSG-code ...
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1answer
40 views

Draw a polygon from the mentioned data

I want to draw a polygon from the below JSON data from a GeoJSON file. However I am confused about the coordinates array since I believed they corresponded to a latitude and a longitude. But clearly ...
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1answer
29 views

Geocortex and ArcMap

I am currently working with a shapefile made up of multi-part polygons symbolizing zoning areas. Geocortex is a web-based service used to display your data. When I click on a larger polygon in ArcMap ...
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1answer
26 views

PostGIS - “parse error - invalid geometry” after using ST_Multi - but ST_IsValid returns true

I have a database with OpenStreetMap polygons, points and relations in separate tables. Now I wanted to build selection queries for the different features and created schemas for each zoom level (5k, ...
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21 views

Iteration between different polygons in one layer

I am trying to create a code that will calculte the mean NDVI value for each polygon,the standard deviation , then std/2 and then will classify the pixels inside each polygon according to the next ...
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1answer
35 views

Sorting polygons into a n x n spatial array

I have a square group of contiguous polygons: By using the centroid coordinates of each polygon, I want to assign each polygon's spatial sequence in a row by row fashion: I have tried this ...
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204 views

Accessing watershed boundary for lakes in R

I have had success accessing unique database IDs and polygons for various lakes in the US. I'm now looking to get polygons for the watersheds associated with these lakes, but have stumbled a bit. ...
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35 views

Why extract returns NAs on the boundary when polygons exactly overlap with the rasters in R?

I'm new to GIS and English is not my first language, so apologies for anything inappropriate. I'm trying to use extract() to get mean values of rasters inside polygons. One of the R codes I used are ...
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1answer
33 views

Centroid of multiple polygons based on value in attribute table

I have a (polygon) shapefile with multiple zones. Now, I would like to calculate the centroid of groups of these zones. The zones have to be grouped based on a value in the attribute table: AreaNr ...
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2answers
56 views

Python, create a polygon from range of three lat/lon points

I have three lat/lon points, I need to use those in order to create a range of all possible points within the polygon that the first three create. Test every lat/lon if it matches a condition I have ...
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2answers
74 views

Get waterbody info from base map in Leaflet

I am plotting points on a map using Leaflet, and would like to collect any data I can concerning the water bodies that encompass these points. I have been making use of polygons from HydroSHEDS (...
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31 views

Converting triangle mesh polygon into square cells

I have a triangle mesh polygon feature class. I would like to convert it to raster-like cells but still as a polygon feature class using ArcGIS Pro. This needs to be at 1m resolution It is ...
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1answer
64 views

Extracting the least area image around a Shapely polygon, with rotation allowed

I have a Shapely polygon polygon_geom = shapely.wkt.loads(feat['wkt']) such as: I can map it onto an image polygon_pts = np.array(list(polygon_geom.exterior.coords)) plt.imshow(img_array_pre) ...
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2answers
60 views

Excel XY to (Multi) Polygons

I'm struggling with visualizing a Excel dataset. I have a Excel data table containing a colum with XY coordinates of (multi)polygons, see the screenshot below. Now, I know that it is possible to ...
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1answer
38 views

QGIS Polygon buffer on only one side

I want to create a buffer on only one side of a polygon. When I create a buffer in the symbology tab in the layer properties, I get the following result: I need a buffer that starts at the outline of ...
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2answers
76 views

Populate field in one layer with corresponding value from another layer

I have 2 existing vector layers: 1 point, 1 polygon. In almost all cases the points overlap a polygon. The point layer has multiple features (1,000+) with an existing field which I need to ...
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1answer
32 views

Skipping TopologyException and continuing operation anyway using R

I'd like to see the result after an hour of working while substracting two shapefiles. This is the code, but don't ask me what in those files. Whatever it is, I'd like to know how to skip those errors ...
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0answers
38 views

Clip completely overlapping polygon(s)

The shapefile that I'm working with (in QGIS) has over more than 250k polygons. But unfortunately a lot of the polygons are overlapping. The focus of my challenge is to delete or clip the polygon ...
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1answer
42 views

Calculating minimum width of polygon using ArcMap

I have a polygon feature that is 228 miles in length and 95 feet in width. But, along the polygon there are sections that are 75 feet wide. I was tasked with locating those sections and flagging them. ...
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1answer
25 views

Adding value options in feature attribute table?

I cannot figure out why it says NULL, my goal is to be able to pick values from a classificator table made in Excel and imported into QGIS as a vector layer.
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31 views

Can't add vertex to polygon in QGIS3

I'm working in QGIS3.8.3 and am trying to use the Vertex Tool to add a vertex to a pre-existing polygon. I expect to be able to do this in an editing session by hovering over the segment in question ...
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1answer
22 views

sf polygon to raster workflow to calculate least cost distance with gdistance in R

I need to calclulate the shortest distance from a set of points to other sets of points in a marine area. Travelling on land must not be possible so I understand I need to calculate the least cost ...
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1answer
51 views

SAGA difference tool in QGIS

I am using QGIS 3.4 Madeira. I want to use difference tool from SAGA from the processing tool box since my data has some invalid geometries and want to fix the issue later after using difference tool ...
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2answers
51 views

With QGIS adjacent polygons, is it possible to “copy” one polygon edge to a new one? Like a “snap to” or “smooth to” the adjacent polygon?

I'm drawing adjacent polygons in QGIS. Whenever I create a new adjacent polygon, or if I've moved a polygon that has an adjacent polygon, I need to adjust the borders of the adjacent polygon to be ...
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0answers
40 views

Combine polygons from different sources

I am currently working on a project where I try to reconstruct historical borders of the austro-hungarian empire between 1815 and 1918. Therfore I use the comination of digitized old maps an legal ...
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29 views

How to count a radius of a polygon

I have a Polygon (shapely) and the centroid of this Polygon (with longitude and latitude). Is there any way to count radius of the Polygon?
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1answer
31 views

Find minimum number of polygons connecting two points

Given GIS data of polygons and two points, is there a way to find the minimum number of polygons you need to traverse to walk between the two points? Even an approximate approach would be fine for my ...
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1answer
50 views

gdal.Warp -cutline option (geometry object instead of vector file)

I am new to ogr and vector data manipulation. I am interested to cut an image (in this case a DEM file) using gdal.Warp() with the '-cutline' option to used the borders of a rectangular polygon to ...
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0answers
34 views

Python GDALwarp cut a raster with a shapefile polygon

I am trying to create a program that cuts multiple rasters in different folders with gdalwarp, the program works for square shapefiles but when I enter one with a polygon the program does not cut ...
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1answer
34 views

GDAL Warp cutline invalid

I'm attempting to crop a raster with gdal warp using python bindings, the code works fine as I use it to crop a raster approximately 3k times, of which a couple fail with the following error and ...
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1answer
160 views

Split polygon in equal parts in QGIS [duplicate]

I have a polygon of an area of 46,465m² and a perimeter of 136,1m. It is a rectangular polygon and I want to split it into three equal parts (which are my treatment blocks). Could anybody give me ...
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0answers
37 views

One polygon layer for an area with different projects in the same layer?

I was wondering if it is possible (maybe not ?) to make a structure so that I can have diffrient information (projekts) over the same area/point in the same layer. This would be for an overview of the ...