[R-sig-eco] simper

2010-02-09 Thread magali proffit
Hi, Does anyone know if the SIMPER (similarity percentage) analysis exists in R? It is implemented in the statistical package PRIMER and is frequently used in biological studies to compare community diversity. It is a multivariate analysis that shows the contribution of each variable

Re: [R-sig-eco] multiple regression

2010-02-09 Thread Gustaf Granath
Standardized coefficients are not necessarily a bad idea. Gelman A., 2008. Scaling regression inputs by dividing by two standard deviations. Stat Med. 2008, 27:2865-73. GG ...and you can also read in Frank Harrell's book why standardized coefficients are a bad idea. There is a large

Re: [R-sig-eco] Multinomial logist regression

2010-02-09 Thread Michael Denslow
Hi Steve, Hi, I've been working up a dataset of soils and vegetation and I'd like to run a multinomial regression model with this data.  The data includes six possible outcomes (vegtation types) and anywhere from 1 to 5 independent predictors (nutrient and hydrological properties).  I've