Top "Polygon" questions

For issues relating to the creation, manipulation and rendering of polygons in graphical user interfaces.

Inserting coordinates into MySQL - PolyFromText SQL syntax error / returning null

I'm trying to insert geographic coordinates of a polygon into my MySQL database. I have a field named polygon of …

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mysql polygon geospatial spatial
How can I split a Polygon by a Line?

As shown below, Is it possible to split a Polygon by a Line? (into two Polygons). If the line doesn't …

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algorithm split polygon
Find the corners of a polygon represented by a region mask

BW = poly2mask(x, y, m, n) computes a binary region of interest (ROI) mask, BW, from an ROI polygon, …

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matlab geometry computer-vision polygon corner-detection
GeoJSON MultiPolygon with multiple holes

Below I have what I'd expect is a way to create a GeoJSON MultiPolygon object with one polygon in it …

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polygon geojson
How to attach a simple data.frame to a SpatialPolygonDataFrame in R?

I have (again) a problem with combining data frames in R. But this time, one is a SpatialPolygonDataFrame (SPDF) and …

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r merge polygon spatial dataframe
Polygon intersection error in Shapely: "shapely.geos.TopologicalError: The operation 'GEOSIntersection_r' produced a null geometry"

I have been trying to debug this problem but unable to do so. I am trying to find the intersection …

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python exception polygon intersection shapely
Create convex hull polygon from points and save as shapefile

Needing some help re a conversion problem in R. I've got calculated the convex hull of a cloud of points. …

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r polygon shapefile
Export a polygon from an R plot as a shapefile

I have been trying to export the content of a plot (lines/polygons) as a layer/shapefile that I can …

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r export polygon shapefile
How can you find the centroid of a concave irregular polygon in JavaScript?

How can you find the centroid of a concave irregular polygon given its vertices in JavaScript? I want to pass …

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javascript polygon
In PostGIS, how do I find all points within a polygon?

I am using PostgreSQL with the GIS extension to store map data, together with OpenLayers, GeoServer etc. Given a polygon, …

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polygon postgis