Hi R-Helpers, I am stuck with my analysis. I wonder if anybody could have with this. My data set looks like: Squares Hours SppRichness Feeding_guild natprop 1 10 1 aq inverts 0.118697 2 25 2 aq inverts 0.605874 3 35 2 fish 0.61255 4 20 4 fish 0.764418 5 40 3 insects 0.810646 6 20 2 insects 0.832063 7 20 2 Omnivores 0.838509 n 20 3 Omnivores 0.839228 My interest is to run a GLM model between the response variable y SppRichness (species richness) and y = natprop )Proportion of Natural Area considering each Feeding Guild (factor) separately. In other words I want to run with one single code the richness within guild as a function of natural proportion area. Is there a way to write a code to run all the correlations for each guild at once? And then to keep the coefficients? And plot the correlations in separately files? Thanks in advance. Rafael -- ********************************************** RAFAEL CAMARGO Postgraduate Student Biology Department of University of Ottawa 30 Marie Currie, room # 251 Ottawa, ON, CANADA Tel: +1 (613) 562-5800 ext. 6366 Cel: +1 (613) 869-3772 e-mail: rcama081@uottawa.ca rafael.x.camargo@gmail.com [[alternative HTML version deleted]]