On Fri, 21 Dec 2007, Johannes Graumann wrote: > <posted & mailed> > > Dear all, > > I'm trying to solve the problem, of how to find clusters of values in a > vector that are closer than a given value. Illustrated this might look as > follows: > > vector <- c(0,0.45,1,2,3,3.25,3.33,3.75,4.1,5,6,6.45,7,7.1,8) > > When using '0.5' as the proximity requirement, the following groups would > result: > 0,0.45 > 3,3.25,3.33,3.75,4.1 > 6,6.45 > 7,7.1
Try this: > tmp <- rle( diff(v)<.5 ) > ends <- 1+cumsum(tmp$lengths)[tmp$values] > mapply(function(x,y) v[ seq(to=x,length=y) ], ends, 1+tmp$lengths[tmp$values]) [[1]] [1] 0.00 0.45 [[2]] [1] 3.00 3.25 3.33 3.75 4.10 [[3]] [1] 6.00 6.45 [[4]] [1] 7.0 7.1 HTH, Chuck > > Jim Holtman proposed a very elegant solution in > http://tolstoy.newcastle.edu.au/R/e2/help/07/07/21286.html, which I have > modified and perused since he wrote it to me. The beauty of this approach > is that it will not only work for constant proximity requirements as above, > but also for overlap-windows defined in terms of ppm around each value. > Now I have an additional need and have found no way (short of iteratively > step through all the groups returned) to figure out how to do that with > Jim's approach: how to figure out that 6,6.45 and 7,7.1 are separate > clusters? > > Thanks for any hints, Joh > > ______________________________________________ > 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. > Charles C. Berry (858) 534-2098 Dept of Family/Preventive Medicine E mailto:[EMAIL PROTECTED] UC San Diego http://famprevmed.ucsd.edu/faculty/cberry/ La Jolla, San Diego 92093-0901 ______________________________________________ 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.
