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rpolygonspatial

Creating polygons from sparse data in R


I have a dataframe with coordinates for which I want to create polygons, the most normal is a polygon like the one I put in the first image:

enter image description here

But I'm looking for something different, more like this: enter image description here

As you can see, if the points are enough far, another polygon is created, is this possible in R? Thanks!

Here are the data csv


Solution

  • I think you would find the concept of concave/alpha hulls relevant. There's an R package alphahull that may cover your need.

    install.packages("alphahull")
    library(alphahull)
    fff <- readr::read_csv("data.csv")
    dddd <- ahull(fff[,2:3],alpha = 0.01)
    plot(dddd)
    

    And in case you need to convert this output into a spatial data format, please see the following: https://babichmorrowc.github.io/post/2019-03-18-alpha-hull/