How do you plot multiple LME residual plots in one device?

stuff from the grid() package can be used to set up viewports, etc., but the simplest method is with the grid.arrange() function from the gridExtra package

library('nlme')

set.seed(101)

treatment <- factor(c(rep("a",4),rep("b",4),rep("c",4)))

response <- rnorm(12,2,1)

explanatory <- rnorm(12,4,1)

test.lme <- lme(response~explanatory,random=~1|treatment)

library('gridExtra')

p1 <- plot(test.lme)

p2 <- plot(form=sqrt(abs(resid(.)))~fitted(.),test.lme)

grid.arrange(p1,p2)

We can also specify no columns and rows for it.