Hi Listers, I am running a partial RDA analysis and I have an environmental dataset which includes a non-ordered factor representing reef type.
I want to test for a significant linear trend in the environmental dataset as part of the process of testing for spatial autocorrelation. e.g. lineartest <- anova(rda(env,latlong)) I have coded this Factor variable up as a group of dummy variables equal to the number of different reef types to run the test but I am unsure if I need to drop one of the dummy variables before running the linear test? I will revert back to a single Factor variable when I run the RDA as told in the vegan documentation? My reading tells me that the call to RDA in Vegan will automatically deal with creating dummy variables from a Factor variable presented in the model but this is not the case cheers Andy Andrew Halford Ph.D Research Scientist (Kimberley Marine Parks) Dept. Parks and Wildlife Western Australia Ph: +61 8 9219 9795 Mobile: +61 (0) 468 419 473 [[alternative HTML version deleted]] _______________________________________________ R-sig-ecology mailing list R-sig-ecology@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-ecology