[Rd] serializing recordedplot object

[Jeroen Ooms]

I use recordPlot() to save plots to disk that I render later to a
variety of formats. This works fine for base R plots and ggplot2
plots, and also used to work for lattice plots. However somewhere in
version 2.14 things stopped working for lattice plots. Here is an
example:

library(lattice);
histogram(rnorm(100));
x <- recordPlot();
saveRDS(x, "myplot.rds");
y <- readRDS("myplot.rds");
print(y);
Error: NULL value passed as symbol address

printing x works fine, but printing y either gives an error or prints
an empty page. The problem seems to be related to serializing the
recordedplot object, which contains a lot of memory pointers. Any tips
or workarounds?

> sessionInfo()
R version 2.14.1 (2011-12-22)
Platform: i686-pc-linux-gnu (32-bit)

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
 [3] LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
 [5] LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8
 [7] LC_PAPER=C                 LC_NAME=C
 [9] LC_ADDRESS=C               LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

other attached packages:
[1] lattice_0.20-0

loaded via a namespace (and not attached):
[1] grid_2.14.1