[R-sig-Geo] Assessing and ranking the relationships and contribution of environmental correlates to species richness

2011-07-03 Thread ah3881
I am trying to run some analysis to determine the percentage contribution of various factors (minimum temp in lgm, npp, etc) on determining species richness of 171 species throughout Southeast Asia (on a km by km basis-so over 4 million rows of cells, and about 14 columns). I have read about variou

Re: [R-sig-Geo] Assessing and ranking the relationships and contribution of environmental correlates to species richness

2011-07-03 Thread Mathieu Rajerison
Hi, How is represented your data: a regular grid: raster, irregular samples: points, or slots/parcels: areas? If you want to determine species richness, you can use simpson and shannon indexes with diversity package. On a point pattern object, use spatstat::marktable function as mentionned in h

Re: [R-sig-Geo] Assessing and ranking the relationships and contribution of environmental correlates to species richness

2011-07-04 Thread ah3881
Hi Thanks. I have species richness projections (made using Maxent projections of species distribution of 171 species, reclassified to give binary estimates of species distributions {10 percentile training threshold) before combining all 171 projections). So I have a raster of species richness in a

Re: [R-sig-Geo] Assessing and ranking the relationships and contribution of environmental correlates to species richness

2011-07-06 Thread Mathieu Rajerison
So, it seems you have one raster for your dependent variable: species richness and one for each explanatory variable. I have never accomplished this but I think you should make a raster stack of all these variables using raster package: the dependent one + the explanatory ones then fit a model, fo