[R-sig-eco] residuals in RDA, and test for spatial autocorrelation
Hello List, I have two questions. 1.)How do I generate a matrix of residuals in RDA (I am using rda() in vegan)? 2.)How can I test for spatial dependence (spatial autocorrelation) in the response matrix of a multivariate analysis (RDA in my case)? I have read that you can look at the trace of the variogram matrix as a multivariate alternative to Moran's I, but I don't know the details of how to make this test happen using R. Thanks for any help! Tracy [[alternative HTML version deleted]] ___ R-sig-ecology mailing list R-sig-ecology@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
[R-sig-eco] adjusting for empty rows in metaMDS
Hello, I am trying to use metaMDS (or isoMDS) for a community data set with 10 species. However, I have several sites with no species present (empty rows), and this seems to present a problem in the dissimilarity matrix in the form of missing values. Does anyone have suggestions on how to deal with this? Is it appropriate to create a dummy variable in the original community matrix? If so, what is the best way to do this? Thanks for any help. Tracy Pinney PhD candidate Department of Biology Baylor University One Bear Place 97388-7388 Waco, TX 76798-7388 [[alternative HTML version deleted]] ___ R-sig-ecology mailing list R-sig-ecology@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
