---------------------------------------------------------------------- Message: 1 Date: Sun, 12 Nov 2017 15:50:14 +0000 (UTC) From: moses selebatso <selebatsom at yahoo.co.uk> To: R-sig-mixed-models <r-sig-mixed-models at r-project.org> Subject: [R-sig-ME] Negative and zero value on mixed models Message-ID: <435089419.992213.1510501814061 at mail.yahoo.com> Content-Type: text/plain; charset="UTF-8" Good day I am trying?to run mixed models on my dataset.?Values range from 1 to?-1,?including zero. I tried to search and?find out if there is any particular way I should handle this data when running mixed models. Moses? [[alternative HTML version deleted]]
Have a look at the pdf file that comes with the betareg package, and see whether the beta distribution (after converting it to the 0 - 1 range) is something that would work for you. If so, then use glmmTMB to fit a beta model with random effects. https://cran.r-project.org/web/packages/betareg/vignettes/betareg.pdf Such an approach assumes that you *cannot* sample a value larger than 1, or smaller than -1. Alain
Dr. Alain F. Zuur Highland Statistics Ltd. 9 St Clair Wynd AB41 6DZ Newburgh, UK Email: highstat at highstat.com URL: www.highstat.com And: NIOZ Royal Netherlands Institute for Sea Research, Department of Coastal Systems, and Utrecht University, P.O. Box 59, 1790 AB Den Burg, Texel, The Netherlands Author of: 1. Beginner's Guide to Spatial, Temporal and Spatial-Temporal Ecological Data Analysis with R-INLA. (2017). 2. Beginner's Guide to Zero-Inflated Models with R (2016). 3. Beginner's Guide to Data Exploration and Visualisation with R (2015). 4. Beginner's Guide to GAMM with R (2014). 5. Beginner's Guide to GLM and GLMM with R (2013). 6. Beginner's Guide to GAM with R (2012). 7. Zero Inflated Models and GLMM with R (2012). 8. A Beginner's Guide to R (2009). 9. Mixed effects models and extensions in ecology with R (2009). 10. Analysing Ecological Data (2007).