I would like to make a NMDS with biomass of different prey groups in stomach content of fish.
I have already made one where the data matrix consists of 0 and 1, and this one went fine but are not able to do it when adding the actual weights.
I have used the MASS and vegan package. When using binomial data matrix:
mymetaMDS <- metaMDS(comm, distance = "jaccard", na.rm = TRUE, binomial = TRUE)
and this works fine.
But when I try to create the dissimilarity matrix with the weight data matrix:
mymetaMDS <- metaMDS(comm, distance = "jaccard", na.rm = TRUE, binomial = FALSE)
Error in if (any(dist < -sqrt(.Machine$double.eps))) warning("some dissimilarities are negative -- is this intentional?") : missing value where TRUE/FALSE needed In addition: Warning messages: 1: In distfun(comm, method = distance, ...) : you have empty rows: their dissimilarities may be meaningless in method "jaccard" 2: In distfun(comm, method = distance, ...) : missing values in results
Any suggestions any one?