This would be a good question for R-sig-geo. To do it properly, there would be a few steps:
1. transform from lat/long (units=degrees) to projected coordinate system (units = meters) 2. find one of the R functions for calculating distances (there are several) 3. subset the data according to your distance threshold The sp package provides a lot of the fundamental tools for these kinds of things. The spDists() function in the sp package may take care of both steps 1 and 2. The overhead required to learn R's spatial capabilities can be significant, but I think will be worth it if you will be needing to do a lot of spatial manipulations. -Don -- Don MacQueen Lawrence Livermore National Laboratory 7000 East Ave., L-627 Livermore, CA 94550 925-423-1062 On 6/17/16, 10:26 AM, "R-help on behalf of Alice Domalik" <r-help-boun...@r-project.org on behalf of adoma...@sfu.ca> wrote: >Hi List, > >I'm working with some bird tracking data, and to filter the data set, I >need to exclude points taken at the colony. >I would like to exclude coordinates from within a 500 meter radius of a >point centered on the colony. >However, as an R novice, I'm not sure how to accomplish this. > >My df looks like this: > >AnimalID Latitude Longitude Datetime > >Any suggestions would be greatly appreciated. > > > [[alternative HTML version deleted]] > >______________________________________________ >R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide >http://www.R-project.org/posting-guide.html >and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.