I'm trying to perform a mantel test that ignores specific pairs in my distance matrices. The reasoning is that some geographic distances below a certain threshold suffer from spatial autocorrelation, or perhaps ecological relationships become less relevant that stochastic processes above a certain threshold.
The problem is that I can't find a way to do it. If I replace values in either or both of the distance matrices with NA, mantel.rtest (ade4 package) gives the following error: Error in if (any(distmat < tol)) warning("Zero distance(s)") : missing value where TRUE/FALSE needed Here's a trivial example that tries to exclude elements of the first matrix that equal 11: library(ade4) a <- matrix(data = 1:36, nrow = 6) b <- matrix(data = 1:36, nrow = 6) a[a==11] <- NA mantel.rtest(as.dist(a), as.dist(b)) Is there a way to do this, either with this package or another? ______________________________________________ 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.