Re: [Qgis-user] The theory behind topology

[Nicolas Cadieux via QGIS-User]

Thanks!

I was trying to find the right terms for the Google search.  This and the other 
link that people shared is exactly what I needed.

Nicolas Cadieux
https://gitlab.com/njacadieux

> Le 11 janv. 2023 à 10:26, David Strip  a écrit :
> 
>  If you're asking the more general question about various geometric 
> algorithms (like intersection, union, inclusion, etc) you might want to look 
> at a text on computational geometry.
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Re: [Qgis-user] The theory behind topology

[David Strip via QGIS-User]

  
  
If you're asking the more general question about various geometric
algorithms (like intersection, union, inclusion, etc) you might want
to look at a text on computational geometry.
  

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Re: [Qgis-user] The theory behind topology

[Luigi Pirelli via QGIS-User]

usually all is based on JST test set. FYI
https://en.wikipedia.org/wiki/JTS_Topology_Suite

Luigi Pirelli

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On Wed, 11 Jan 2023 at 04:24, Nicolas Cadieux via QGIS-User <
qgis-user@lists.osgeo.org> wrote:

> Hi,
>
> I am curious to learn the math behind topology.  For example, I would like
> to know how something like “selecting points in a polygon “ is actually
> done from a programming point of view.  If you have a good resource (books,
> video, articles…) please send it my way.
>
> Thanks
>
> Nicolas Cadieux
> https://gitlab.com/njacadieux
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Re: [Qgis-user] The theory behind topology

[Nicolas Cadieux via QGIS-User]

Thanks!

Nicolas Cadieux
https://gitlab.com/njacadieux

> Le 10 janv. 2023 à 23:37, Terry Morse via QGIS-User 
>  a écrit :
> 
> 
> Principles of Geographical Information Systems, by Burrough and McDonnell 
> (Oxford: Oxford Univ. Pr., 1998; ISBN 0198233655) has a brief treatment of 
> point-in-polygon on page 64 (box 3.4), or see Principles of Geographical 
> Information Systems, 3rd ed., by Burrow, McDonnell, and Lloyd (Oxford: Oxford 
> Univ. Pr. 2015; ISBN 0198742845), where it is Box 7.3 on page 140. It may not 
> be as detailed as you want, but it's a beginning. Wikipedia has an article 
> with a little more detail at https://en.wikipedia.org/wiki/Point_in_polygon 
> that includes references.
>  
> There are scripts at 
> https://www.geeksforgeeks.org/how-to-check-if-a-given-point-lies-inside-a-polygon/
>  in both c++ and python.
>  
> Terry Morse
> tmo...@teleport.com
>  
> -Original Message-
> From: Nicolas Cadieux 
> Sent: Jan 10, 2023 7:23 PM
> To: Qgis List 
> Subject: [Qgis-user] The theory behind topology
> 
>  
> Hi,
> 
> I am curious to learn the math behind topology.  For example, I would like to 
> know how something like “selecting points in a polygon “ is actually done 
> from a programming point of view.  If you have a good resource (books, video, 
> articles…) please send it my way.
>  
> Thanks
> 
> Nicolas Cadieux
> https://gitlab.com/njacadieux
>  
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Re: [Qgis-user] The theory behind topology

[Terry Morse via QGIS-User]

Principles of Geographical Information Systems, by Burrough and McDonnell 
(Oxford: Oxford Univ. Pr., 1998; ISBN 0198233655) has a brief treatment of 
point-in-polygon on page 64 (box 3.4), or see Principles of Geographical 
Information Systems, 3rd ed., by Burrow, McDonnell, and Lloyd (Oxford: Oxford 
Univ. Pr. 2015; ISBN 0198742845), where it is Box 7.3 on page 140. It may not 
be as detailed as you want, but it's a beginning. Wikipedia has an article with 
a little more detail at https://en.wikipedia.org/wiki/Point_in_polygon that 
includes references.

There are scripts at 
https://www.geeksforgeeks.org/how-to-check-if-a-given-point-lies-inside-a-polygon/
 in both c++ and python.

Terry Morse
tmo...@teleport.com (mailto:tmo...@teleport.com)

-Original Message-
From: Nicolas Cadieux 
Sent: Jan 10, 2023 7:23 PM
To: Qgis List 
Subject: [Qgis-user] The theory behind topology

Hi,
I am curious to learn the math behind topology.  For example, I would like to 
know how something like selecting points in a polygon  is 
actually done from a programming point of view.  If you have a good resource 
(books, video, articles) please send it my way.
 
Thanks

Nicolas Cadieuxhttps://gitlab.com/njacadieux





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[Qgis-user] The theory behind topology

[Nicolas Cadieux via QGIS-User]

Hi,

I am curious to learn the math behind topology.  For example, I would like to 
know how something like “selecting points in a polygon “ is actually done from 
a programming point of view.  If you have a good resource (books, video, 
articles…) please send it my way.

Thanks

Nicolas Cadieux
https://gitlab.com/njacadieux___
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