I am trying to apply nmds to a data matrix but I receive the
following error message:
Error in isoMDS(dis, y = y, k = k, maxit = maxit) :
zero or negative distance between objects 5 and 7
The data are in a vegetation cover-class matrix (species in columns,
plots in rows, classes 1-8 with lots of zero values) converted to a
dissimilarity matrix (bray curtis).
I assumed that objects 5 and 7 refer to rows of my original data; and
they do have the same species with the same cover classes. I deleted
one of these rows but I received the same error message with a rerun
of nmds. As it turns out, the new rows 5 and 7 are the same. How do
I avoid this problem?
Any advice for this neophyte would be greatly appreciated. Thanks!
______________________________________________
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
