Fantastic. Thanks! On Tue, Jul 14, 2015 at 7:03 AM, Jim Lemon <drjimle...@gmail.com> wrote:
> Hi Karla, > This might help. I haven't tested it exhaustively. > > transect_overlap<-function(x) { > if(!is.matrix(x)) stop("x must be a 2x2 matrix") > if(x[1,1] <= x[2,1]) { > if(x[2,2] > x[1,2]) overlap<-x[1,2]-x[2,1] > else overlap<-x[2,2]-x[2,1] > } > else { > if(x[1,2] > x[2,2]) overlap<-x[2,2]-x[1,1] > else overlap<-x[1,2]- x[1,1] > } > if(overlap < 0) overlap<-0 > return(overlap) > } > > Jim > > > On Tue, Jul 14, 2015 at 7:44 AM, Karla Shikev <karlashi...@gmail.com> > wrote: > > Hi there, > > > > This is a newbie question, and I'm sure there are simple ways to do this, > > but I've spent my entire afternoon and I couldn't get it to work. > > > > Imagine that I got my samples distributed along a transect and my data > > refer to the first and last occurrences of each sample. For instance: > > > >> dat<-matrix(c(1,3,2.5,4), ncol=2, byrow=TRUE) > >> dat > > [,1] [,2] > > [1,] 1.0 3 > > [2,] 2.5 4 > > > > > > The first line indicates that the first and last occurrences of this > > subject were 1 and 3, respectively, whereas the second subject was found > > between 2.5 and 4. > > > > I need a simple way to calculate the overlap of their extents (0.5 in > this > > case). This way should provide 0 if there is no overlap, and it should > also > > work in the case where one subject is found only within the extent of the > > second subject. > > > > Any help will be greatly appreciated. > > > > Karla > > > > [[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. > [[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.