Prof Brian Ripley wrote: > On Wed, 12 Oct 2005, David Zhao wrote: > > >>Does anybody have experience in running jpeg device using xvfb-run on >>linux? I've been having sporadic problem with: /usr/X11/bin/xvfb-run >>/usr/bin/R --no-save < Rinput.txt, with error saying: error in X11 >>connection. Especially when I run it from a perl script. > > > Not sure what `xvfb-run on Linux' is, as it is not on my Linux (FC3). > If you Google it you will find a number of problems reported on Debian > lists. Here I would suspect timing. > > What I do is to run Xvfb on screen 5 by > > Xvfb :5 & > setenv DISPLAY :5 > > and do not have a problem with the jpeg() or png() devices. I do have a > problem with the rgl() package, but then I often do on-screen (on both 32- > and even more so 64-bit FC3).
For R-embedded-in-Python (via RPy) on a Web server, we have been using a Python programme to automatically start Xvfb if it is not already running. You can find a copy of the programme in the NetEpi-Analysis tarball available at http://sourceforge.net/project/showfiles.php?group_id=123700 The tricky bit is managing the permissions for the Xvfb session, particularly in a Web server context - you need to take care. However, this use of Xvfb has been perfectly reliable (on Red Hat Enterprise Linux 2.1 and 3 with R2.0 and R 2.1) > >>Is there a better way of doing this? or how can I fix the problem. > > You really should update your R. Yes. We now use GDD, which is an alternative R graphics driver for raster graphics (Jpeg and PNG), available via CRAN. It allows R to directly generate jpeg and png files on a Linux or Unix machine without the need for an X server to be running (not even Xvfb). The quality of the output is also better than the standard R X11/png/jpeg graphics device due to the use of anti-aliased fonts by GDD. Earlier versions of GDD were a bit buggy, but so far we have found the latest version (0.1.7) to be fine. It is a bit fiddly to install all the libraries it requires as well as the recommended (no-cost) Microsoft TrueType fonts, but the effort is worth it. Many thanks to Simon Urbanek for his work on GDD. Tim C ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html