Running R on a Linux server in headless mode (i.e. producing graphics without XWindows running) can be tricky. Some people recommend using a virtual X framebuffer. However, I’ve found that the best approach (at least im my opinion) is to use the R interface to Cairo. This allows R to produce png graphics in headless mode, and also produces very nice looking graphs. I configured R as follows (after downloading and building pixman-0.15.18, and cairo-1.8.8:
./configure --with-gnu-ld --with-x --with-cairo
This will produce an R binary with cairo support that can be run non-interactively and produce graphical output – very useful for running automated statistical reports.
You can check that Cairo support is enabled by checking the return value of the capabilities() function:
> capabilities()
jpeg png tiff tcltk X11 aqua http/ftp sockets
TRUE TRUE FALSE FALSE FALSE FALSE TRUE TRUE
libxml fifo cledit iconv NLS profmem cairo
TRUE TRUE TRUE TRUE TRUE FALSE TRUE
Finally, some notes on connecting X11 clients using Cygwin (which I always forget how to do). On the server, check /etc/ssh/sshd_config for the line
X11Forwarding yes
And then run a local X server:
XWin -clipboard -emulate3buttons -multiwindow
Once this is running, from an xterm, run ssh, passing in the -X argument to enable X forwarding.
ssh -X -l username myserver
X11-based applications can then be run from this session.
