I would like to plot grid objects and base R objects on the same png. The package I am using the meta package to make forest plots uses the grid graphics system.

I would like to use mfrow for this if possible, as it is what I am using elsewhere.

If I plot:

png("test.png",width=297,height=210,units="mm",res=300)
par(mfrow=c(2,2))
plot(1,1)
plot(1,1)
plot(1,1)
plot(1,1)
dev.off()

Everything works fine.

However if I plot:

library(meta)
m <- metaprop(4:1, c(10, 20, 30, 40))
png("test.png",width=297,height=210,units="mm",res=300)
par(mfrow=c(2,2))
plot(1,1)
forest(m,new=F)
plot(1,1)
forest(m,new=F)
dev.off()

Things aren't right as the forest plots try to take up the whole page rather than being restricted to their corners.

Thanks in advance for your help