HI Diane, Sorry for the delay. You can't place a prior directly on the heritability in MCMCglmm (you would have to use JAGS/WinBUGS to do that). You can place priors on the variance components though. You have the choice of inverse Wishart priors (aka inverse gamma or inverse scaled chi-square in the univariate case) or parameter expanded priors (setting nu=1 and alpha.mu=0 you have a scaled F(1,1) prior). The inverse Wishart prior is the easiest to understand: placing a prior of V=2, nu=1 on the additive genetic variance is equivalent to having a prior observation of a single breeding value of value sqrt(V). A prior of this strength sounds innocuous but it can have a surprisingly strong effect. Cheers, Jarrod Quoting Diana Caro <dianacaro0918 at hotmail.com> on Mon, 26 Jan 2015 09:58:46 -0500:
Hi! I want to estimate variance components for four weight traits in a multivariate model.If I have prior information of variances or heritabilities (from literature), how can I incorporate this information in a prior? Thanks Diana [[alternative HTML version deleted]]
_______________________________________________ R-sig-mixed-models at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models
The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.