Hi all, I am working with a spatial data set for which I am only interested in high concentration values ("leaks"). The low values (< 90th percentile) have already been turned into NA's, leaving me with a matrix like this:
< CH4_leak lon lat CH4 1 -71.11954 42.35068 2.595834 2 -71.11954 42.35068 2.595688 3 NA NA NA 4 NA NA NA 5 NA NA NA 6 -71.11948 42.35068 2.435762 7 -71.11948 42.35068 2.491003 8 NA NA NA 9 -71.11930 42.35068 2.464475 10 -71.11932 42.35068 2.470865 Every time an NA comes up, it means the "leak" is gone, and the next valid value would represent a different leak (at a different location). My goal is to tag all of the remaining values with an indicator variable to spatially distinguish the leaks. I am envisioning a simple numeric indicator such as: lon lat CH4 leak_num 1 -71.11954 42.35068 2.595834 1 2 -71.11954 42.35068 2.595688 1 3 NA NA NA NA 4 NA NA NA NA 5 NA NA NA NA 6 -71.11948 42.35068 2.435762 2 7 -71.11948 42.35068 2.491003 2 8 NA NA NA NA 9 -71.11930 42.35068 2.064475 3 10 -71.11932 42.35068 2.070865 3 Does anyone have any thoughts on how to code this, perhaps using the NA values as a "break point"? The data set is far too large to do this manually, and I must admit I'm completely at a loss. Any help would be much appreciated! Best, Max [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list 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.