Hi Alesandro, You could try using the manyglm function in the mvabund package, and using size of univariate test statistics as a measure of variable importance. This is a more reliable indicator than SIMPER and will work with any fixed effects design. All the best David
Professor David Warton School of Mathematics and Statistics, Evolution & Ecology Research Centre, Centre for Ecosystem Science UNSW Sydney NSW 2052 AUSTRALIA phone +61(2) 9385 7031 fax +61(2) 9385 7123 http://www.eco-stats.unsw.edu.au -----Original Message----- From: R-sig-ecology <r-sig-ecology-boun...@r-project.org> On Behalf Of r-sig-ecology-requ...@r-project.org Sent: Saturday, 24 March 2018 10:00 PM To: r-sig-ecology@r-project.org Subject: R-sig-ecology Digest, Vol 120, Issue 6 Send R-sig-ecology mailing list submissions to r-sig-ecology@r-project.org To subscribe or unsubscribe via the World Wide Web, visit https://stat.ethz.ch/mailman/listinfo/r-sig-ecology or, via email, send a message with subject or body 'help' to r-sig-ecology-requ...@r-project.org You can reach the person managing the list at r-sig-ecology-ow...@r-project.org When replying, please edit your Subject line so it is more specific than "Re: Contents of R-sig-ecology digest..." Today's Topics: 1. Good alternative to SIMPER analysis for continuous variables? (Alessandro Manfrin) ---------------------------------------------------------------------- Message: 1 Date: Sat, 24 Mar 2018 06:19:42 +0100 From: Alessandro Manfrin <manf...@igb-berlin.de> To: r-sig-ecology@r-project.org <r-sig-ecology@r-project.org> Subject: [R-sig-eco] Good alternative to SIMPER analysis for continuous variables? Message-ID: <kcim.5ab5dfee.70e0.67e8468773deb...@ucsmail01.ad.igb-berlin.de> Content-Type: text/plain; charset="utf-8" Dear all, I am conducting an analysis in which I have river sites restored and unrestored. Also, these sites are located over different altitudes, latitudes (continuous variables) and in different fish zones (categorical variable). I used ADONIS (diss calculated with Bray Curtis) to assess differences in fish trait composition between restored and unrestored sites including also the interaction with both categorical and continuous variables: Adonis.mod<-diss~Restoration*altitude+Restoration*latitudes+Restoration*fish zones, strata=rivers Now I would like to use SIMPER analysis to see which traits are responsable for the difference observed in Restoration*fish zones (categorical variable). What can I use to understand which are the traits that are resonsable for difference in Restoration*altitude as SIMPER cannot be used for continuous variables? Maybe stupidely I thought to do this: perform RDA (eclidean distance) on the delta values (Rest-Unrestored) and include the significant continuous variable from the ADONIS (i.e. altitude) in the rda analysis and then check visually which are the "species" of traits that are responding to the vector "altitude". Besideds the fact if it makes sense or not to do that, the other doubt that I have with RDA is related to the "random structure=river" for which I would like the rda to account the fact that I collected samples from different rivers in Germany (for which I believe I kind of considered in the Adonis with the function "strata=river" Please tell me if I am wrong and if yes f you have some good suggestions. Best regards Alessandro Dr. Alessandro Manfrin University of Applied Sciences Trier, Umwelt Campus Birkenfeld/ University of Duisburg-Essen, Faculty of Biology Working place: Department of Aquatic Ecology Room S05 T03 B02 Universitätsstr. 5 45141 Essen (DE) Tel.: +49 (0)201/183-3113 Fax: +49 (0)201/183-2179 [[alternative HTML version deleted]] ------------------------------ Subject: Digest Footer _______________________________________________ R-sig-ecology mailing list R-sig-ecology@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-ecology ------------------------------ End of R-sig-ecology Digest, Vol 120, Issue 6 ********************************************* _______________________________________________ R-sig-ecology mailing list R-sig-ecology@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
