On Apr 20, 2011, at 8:35 AM, Karl-Dieter Crisman wrote: >> Message: 12 >> Date: Wed, 20 Apr 2011 02:09:23 -0700 (PDT) >> From: Sharpie <ch...@sharpsteen.net> >> To: r-devel@r-project.org >> Subject: Re: [Rd] How to get R to compile with PNG support >> Message-ID: <1303290563237-3462502.p...@n4.nabble.com> >> Content-Type: text/plain; charset=UTF-8 >> >> >> Dear R devel list, >> >> Good morning; I'm with the Sage (http://www.sagemath.org) project. >> (Some of you might have seen my talk on this at last summer's useR >> conference). >> >> Thanks for stoping by Karl! I have to say that I am a big fan of the Sage >> project---it is a very good idea and I really appreciate all the time you >> guys put into it. I may not be able to answer all of your questions >> concerning PNG support, but hopefully some of the following pointers will be >> useful. > > Good morning, Charlie et al., > > Thanks for your words. We like R, too! We need to advertise it more, > and this thread is part of making sure that happens in the long run. > > To the issue at hand. Our main concern is just not to have to spend > hours reading the configuration and makefile to figure out exactly > where things happen. > > >>> >>> We have some rudimentary support for using R graphics in various >>> cases, which has proved useful to many of our users who want to go >>> back and forth between R and other capabilities within Sage. >>> Unfortunately, the way we originally implemented this was using the >>> png and plot functions in R itself, which perhaps isn't the best >>> (i.e., everyone uses ggplot now? but I digress). >>> >> >> One important distinction to make is between R graphics functions such as >> plot and ggplot, and R graphics *devices*, such as png. The devices provide >> back ends that take the R-level function calls and actually execute the >> low-level "draw line from a to b, clip to rectangle A, insert left-justified >> text at x,y" primitives that get written to an output format. > > > True. It's the device enabling that I'm talking about. We enable > aqua on Mac, and png on Linux. > > We ignore Cairo, and ignore X11 on Mac because it is too touchy (at > least, according to the FAQ on this - different weird instructions for > each type, and of course not everyone has X on Mac). >
FWIW this seem a little outdated - all recent OS X come with X11 installed and libcairo is not a problem to build ... >> Bottom line for Sage is that as long as you implement at least one device >> function, such as png, your users should be able to call plot, ggplot, and >> the rest of R's graphics functions to their heart's content, they just won't >> have a wide selection of output formats. >> > > Great. That is okay with us; we aren't expecting (yet) people to be > able to save R graphics in various output formats. Our native > (matplotlib) graphics, we do expect this. > > >>> Then, not only could we be smarter in how we compile R (currently >>> somewhat naively searching for /usr/include/X11/Xwindows.h to >>> determine whether we'll try for png support), but we would be able to >>> tell users something very precise to do (e.g., apt-get foo) if they >>> currently have R without PNG support in Sage. Again, I emphasize that >>> apparently getting xorg-dev doesn't always do the trick. >>> > > >> In the trac ticket you linked, the configure output shows PNG is enabled >> (I.E. the library was found) but you may be ending up with no support for an >> actual png() graphics device due to one of the following >> >> - configure didn't find Xlib as X11 is not listed under Interfaces >> - configure didn't find cairo as it is not listed under Additional >> capabilities >> >> So, although R has the PNG library that is only useful for writing PNG >> files. R also needs the Xlib or Cairo libraries to provide drawing >> primitives that will create the figures those files will contain. > > Gotcha. I suspect that the X11 not listed under Interfaces is the > problem (again, we ignore Cairo). > > What is the *exact* file or directory that the R configure looks for > in trying to list X11 under Interfaces? And is there any way around > this at all? That is, is there any way for R to create but not > display a graphic if it has (for instance) png support, like the one > on the Trac ticket did? We can always just search for the png file > and serve it up in our own viewers. > > Note that we already search for /usr/include/X11/Xwindows.h, and > adding xorg-dev didn't help with the latest one (which may not be on > the Trac ticket). > I missed which distro you're using, but xorg-dev is likely insufficient (by design). For example on Debian you'll also need libxt-dev. Note that your best friend is config.log and the output of configure - that tells *exactly* what you're missing. You will need at least X11, ICE, Xt libraries and X11/Intrinsic.h headers. Cheers, Simon >> In the ask.sagemath question the problem appears to be that the user had X11 >> installed but not libpng. > > Yes, I just referenced that for reference, as it were. > > Thank you, and I hope we can get this resolved! > > Karl-Dieter > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > > ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
