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Questions tagged [polygon]

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

A polygon is a two-dimensional figure that is bounded by a closed path composed of a finite sequence of straight line segments. Polygons are drawn and rendered in graphical user interfaces.

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How to draw a n sided regular polygon in cartesian coordinates?

I have been trying to figure out how to write a simple program to compute the x,y points for creating a regular polygon of n sides. Can someone give me some code examples that don't use preexisting functions that draw polygons? I want to understand…
alphablender
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Find Point in polygon PHP

i have a typical question with the Geometric datatype of mysql, polygon. I have the polygon data, in the form of an array of latitudes and longitudes, ex: [["x":37.628134, "y":-77.458334], ["x":37.629867, "y":-77.449021], ["x":37.62324, …
shasi kanth
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How to draw transparent polygons?

I'm using PIL (Python Imaging Library). I'd like to draw transparent polygons. It seems that specifying a fill color that includes alpha level does not work. Are their workarounds? If it can't be done using PIL I'm willing to use something…
carrier
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Determine if a point reside inside a leaflet polygon

Suppose I Draw a polygan using leaflet like in the follow demo: http://leaflet.github.io/Leaflet.draw/ My question is how I can determine if a given point reside inside the polygon or not.
Majdi Taleb
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How to intersect two polygons?

This seems non-trivial (it gets asked quite a lot on various forums), but I absolutely need this as a building block for a more complex algorithm. Input: 2 polygons (A and B) in 2D, given as a list of edges [(x0, y0, x1, y2), ...] each. The points…
Daren Thomas
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Is there an easy and fast way of checking if a polygon is self-intersecting?

I have a System.Windows.Shapes.Polygon object, whose layout is determined completely by a series of points. I need to determine if this polygon is self-intersecting, i.e., if any of the sides of the polygon intersect any of the other sides at a…
GWLlosa
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mongodb check if point is in polygon

mongo 2.6 I have some amount of stored polygons. And I have a point. I what to know if this point fits any of stored polygons document example { ..., "polygons" : [ [ 17.60083012593064, 78.18557739257812 ], [ 17.16834652544664, 78.19381713867188 ],…
user3806072
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Google Maps v3 - Delete vertex on Polygon

Google Maps has the Drawing library to draw Polylines and Polygons and other things. Example of this functionality here: http://gmaps-samples-v3.googlecode.com/svn-history/r282/trunk/drawing/drawing-tools.html I want, when drawing and editing the…
James F
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Converting a column of Polygons from string to GeoPandas geometry

I have a dataframe stored as csv file, one column of which is Polygon object. However, this column is stored as strings instead of GeoPandas geometry object. How can I convert this column to Geopandas geometry object so that I can perform geo…
xinyuanliu
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How to test if a point is inside of a convex polygon in 2D integer coordinates?

The polygon is given as a list of Vector2I objects (2 dimensional, integer coordinates). How can i test if a given point is inside? All implementations i found on the web fail for some trivial counter-example. It really seems to be hard to write a…
usr
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Center of gravity of a polygon

I am trying to write a PHP function that will calculate the center of gravity of a polygon. I've looked at the other similar questions but I can't seem to find a solution to this. My problem is that I need to be able to calculate the center of…
mixkat
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Efficient extraction of all sub-polygons generated by self-intersecting features in a MultiPolygon

Starting from a shapefile containing a fairly large number (about 20000) of potentially partially-overlapping polygons, I'd need to extract all the sub-polygons originated by intersecting their different "boundaries". In practice, starting from…
lbusett
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How to draw rounded corner polygons on android canvas?

I need to draw polygons like triangle, trapezoid, pentagon, parallelogram, rhombus etc. It seems Path class is way to go, however i need these polygons have rounded corners and i also need to control the amount of the rounding.
user65721
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Initializing Half-edge data structure from vertices

I'm working on implementing various subdivision algorithms (such as catmull-clark); to do this efficiently requires a good way to store information about a grid of tesselated polygons. I implemented the half-edge data structure as outlined by…
nathan lachenmyer
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How to get list of points inside a polygon in python?

I searched a lot and cant find any practical answer to my question. I have a polygon. For example: [(86, 52), (85, 52), (81, 53), (80, 52), (79, 48), (81, 49), (86, 53), (85, 51), (82, 54), (84, 54), (83, 49), (81, 52), (80, 50), (81, 48), …
Farshid Ashouri
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