Dear Esu, About your question there is huge literature already written.
I recommend to read the sp package manual. An example for extract the coordinates you can find it here: https://gis.stackexchange.com/questions/43543/how-to-calculate-polygon-centroids-in-r-for-non-contiguous-shapes If you want to see how works the function remember that r is an open source code and you can find the original functions over the binaries repositories or compressed packages. All the best, Andres On Thu, 20 Dec 2018 at 22:58, Esu Esu via R-sig-Geo <r-sig-geo@r-project.org> wrote: > Dear All, > I am new to R-programming. I have question if anyone can help me with:Q: > how can I create functions in R to compute the area (A), centroid (Cx and > Cy) and perimeter (P) of a polygon list . I want to write R functions to > compute these quantities for individual polygons, as well asan overall > function to take a polygon list and return a data frame with four columns > and the samenumber of rows as polygons in the list. Each quantity > should correspond to each column. it is (sp) class object. > Hope to find any suggestion or answer > RegardsMuhsien > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@r-project.org > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > -- Andrés D. [[alternative HTML version deleted]] _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo