According to this blog post from 2013, the MuMIn
package in R
can provide R$^2$ values for mixed models ala an approach developed by Nakagawa & Schielzeth 2013$^1$ (which was mentioned in a previous answer).
#load packages
library(lme4)
library(MuMIn)
#Fit Model
m <- lmer(mpg ~ gear + disp + (1|cyl), data = mtcars)
#Determine R2:
r.squaredGLMM(m)
R2m R2c
0.5476160 0.7150239
The output for functionr.squaredGLMM
provides:
R2m: marginal R squared value associated with fixed effects
R2c conditional R2 value associated with fixed effects plus the random effects.
Note: a comment on the linked blog post suggests that an alternative Nakagawa & Schielzeth inspired approach developed by Jon Lefcheck (using the sem.model.fits
function in the piecewiseSEM
package) produced identical results. [So you have options :p].
I did not test this latter function, but I did test the
r.squaredGLMM()
function in theMuMIn
package and so can attest that it is still functional today (2018).As for the validity of this approach, I leave reading Nakagawa & Schielzeth (2013) (and follow-up article Johnson 2014$^2$) up to you.
1: Nakagawa, S., and Schielzeth, H. 2013. A general and simple method for obtaining R2 from generalized linear mixed‐effects models. Methods in Ecology and Evolution 4(2): 133-142.
2: Johnson, P. C. D. 2014 Extension of Nakagawa & Schielzeth’s R2GLMM to random slopes models. Methods in Ecology and Evolution 5: 44–946.