alphahull: an R Package for Alpha-Convex Hull | /en/2010/04/alphahull-an-r-package-for-alpha-convex-hull/

yihui 2022-12-16 18:52:59

alphahull: an R Package for Alpha-Convex Hull

https://yihui.org/en/2010/04/alphahull-an-r-package-for-alpha-convex-hull/

3 Comments

giscus-bot 2022-12-16 18:53:00

Guest *Matt Moehr* @ 2010-06-30 00:41:55 originally posted:

Are you saying that R has a function for an alpha convex? I've been looking for something like this for my dissertation work. I'm trying to turn geolocated photographs in publically-available websites (flickr, picasa, photobucket) into definitions of cities, towns, and neighborhoods. So far I have API wrappers written in PHP which dump into MySQL databases. If I can pipe my data into an R program, I can do the whole project open source and free!

Here's a blog that put the idea in my head:
http://code.flickr.com/blog/2008/10/30/the-shape-of-alpha/

yihui 2022-12-16 18:53:03

see the function chull() in base R (and run the example there)

Originally posted on 2010-07-02 11:05:51

giscus-bot 2022-12-16 18:53:01

Guest *Stephen Gregory* @ 2011-01-11 10:44:50 originally posted:

Great job!

giscus-bot 2022-12-16 18:53:02

Guest *Kevin Goulding* @ 2012-03-04 15:22:12 originally posted:

Nice! Is there a way to export the alphahull as a polygon shapefile?

yihui 2022-12-16 18:53:03

I do not know, but I see you have got a reply in the r-help mailing list.

Originally posted on 2012-03-04 20:01:17