[R] Multivariate Regression Trees: how to identify sample units?

2010-09-07 Thread afsouza
Dear friends, I am sudying the mvpart package, that implements Multivariate Regression Trees, aiming at applying it to a biogeographical dataset of tree speces in southern South America. My doubt is how to access plot identities after the tree is produced. For us it is rather important, b

[R] Repeated Procedures

2010-07-26 Thread afsouza
Dear Friends, Using package Vegan, I need to calculate Shannons Diversity index and Pielou's Evenness for a set of 20 study areas. Each area is represented by a matrix of 25 sample plots x tree species. The code is as following, where data stands for the data matrix of any of the 20 areas: S

[R] Factor Loadings in Vegan's PCA

2010-06-30 Thread afsouza
Hi all, I am using the vegan package to run a prcincipal components analysis on forest structural variables (tree density, basal area, average height, regeneration density) in R. However, I could not find out how to extract factor loadings (correlations of each variable with each pca axis)

[R] Factor Loadings in Vegan's PCA

2010-06-30 Thread afsouza
Hi all, I am using the vegan package to run a prcincipal components analysis on forest structural variables (tree density, basal area, average height, regeneration density) in R. However, I could not find out how to extract factor loadings (correlations of each variable with each pca axis)