[R-sig-eco] residuals in RDA, and test for spatial autocorrelation

2014-04-01 Thread Pinney, Tracy A
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

[R-sig-eco] adjusting for empty rows in metaMDS

2012-01-25 Thread Pinney, Tracy A
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