[R] How to make two side-by side trellis plots same size

[Dieter Menne]

Dear Latticers,

I want to position two trellis plots of different forms 
side-by-side. The plot types are slightly different, 
aspect=1 required, but panels should look the same in 
both plots. Current workaround uses a guessed factor. 
Any way to improve this?

Dieter


library(lattice)
n1 = 20
# I cannot rbind df1 and df2, because the x-dimensions are
# different and must be scaled individually
df1 = data.frame(y=rnorm(4*n1),x=rep(1:n1,4),
   facA=rep(c("A","B"),each=2*n1),facB=rep(c("C","D"),each=n1))

# I add a dummy facB here, to make sure panels have same structure
df2 = data.frame(y=rnorm(2*n1),z=rep(100*(1:n1),2),
   facA=rep(c("A","B"),each=n1),facB="C")

# Note: aspect = 1 is required
p1 = xyplot(y~x|facA*facB,data=df1,main="Plot1",aspect=1,
  between=list(x=2))
p2 = xyplot(y~z|facA*facB,data=df2,main="Plot2",aspect=1,layout=c(1,2))

wi = 0.61 # this is trial-and-error
print(p1,position=c(0,0,wi,1),more=T)
print(p2,position=c(wi,0,1,1),more=F)