[R] grouping explanatory variables into "sets" for GLMM

Dear all, I am trying to run a GLMM following the procedure described by Rhodes et al. (Ch. 21) in the Zuur book Mixed effects models and extensions in R . Like in his example, I have four "sets" of explanatory variables: 1. Land use - 1 variable, factor (forest or agriculture) 2. Location - 1

[R] dealing with different kinds of environmental data in one matrix

Hi, I have done a CCA with an environmental data matrix including both relative abundance of plant species, soil properties (continuous, with different units of concentrations), and factors that should explain my species matrix. Only after running the analysis have I realized that I should have d

[R] CCA plot

Hi, I have a couple questions about fitting environmental (land use factors, plant species presence-absence, and soil variables) constraints to my CCA biplot. 1. After successfully plotting species and site scores in my CCA, I have been trying to insert the biplot arrows of the environmental constr