[Rd] How to get R to compile with PNG support

[Karl-Dieter Crisman]

Thanks for your replies, Dirk and Matt.

On Thu, Apr 21, 2011 at 7:49 AM, Dirk Eddelbuettel <edd at debian.org> wrote:
>
> On 20 April 2011 at 12:16, Karl-Dieter Crisman wrote:
> | ++++
> |
> | R is now configured for i686-pc-linux-gnu
> |  Source directory:          .
> |  Installation directory:    /home/sageserver/sage/local
> |  C compiler:                gcc -std=gnu99
> | -I/home/sageserver/sage/local/include
> | -L/home/sageserver/sage/local/lib/   Fortran 77 compiler:
> | sage_fortran  -g -O2
> |  C++ compiler:              g++  -g -O2
> |  Fortran 90/95 compiler:    sage_fortran -g -O2  Obj-C compiler:
> |  Interfaces supported:      X11
> |  External libraries:        readline, BLAS(ATLAS), LAPACK(generic)
> | Additional capabilities:   PNG, NLS
> |  Options enabled:           shared R library, R profiling
> |  Recommended packages:      yes
> |
> |
> | However:
> |
> |
> | > capabilities()
> |    jpeg      png     tiff    tcltk      X11     aqua http/ftp  sockets
> |   FALSE    FALSE    FALSE    FALSE    FALSE    FALSE     TRUE     TRUE
> |
> |  libxml     fifo   cledit    iconv      NLS  profmem    cairo
> |    TRUE     TRUE     TRUE     TRUE     TRUE    FALSE    FALSE
>
> Random guess: did you connect via ssh without x11 forwarding?

Almost certainly, yes.  (I am an interlocutor right now for someone
who is actually doing this, my apologies.)
But it's a machine we just ssh into, I'm pretty sure, though it does
serve up web pages.

> I cannot see how configure find png.h and libpng but the binary fails. As all
> other X11 related formats are also shown false, methinks you are without a
> valid DISPLAY.

That is quite likely.  So it sounds like for png() to be set to use
the X11 device, there has to (somewhere) be a visual output -
presumably that is the part LOGICAL(ans)[i++] = X11; in Matt's answer.

> That is actually an issue related to your headless use---which is what Sage
> may default too; see the R FAQ on this and the prior discussion on the
> xvfb-run wrapper which 'simulates' an x11 environment (which you need for
> png).  So maybe you should revisit the Cairo devices---they allow you
> plotting without an x11 device (and also give you SVG).
>

Yeah, and I saw your SO answer on this (after the fact) as well.

In some sense, we are just trying to get graphics on one machine.
Note that we have installed the cairo devel package on this very
machine, but it's not being picked up - maybe it's looking in the
wrong place?  That is one of the reasons this is confusing.

But in a larger sense, because of Sage's "batteries included"
philosophy (which we know not everyone agrees with!), we would like to
have a one-shot way so that *everyone* will see R graphics, not just
people whose binary happens to have been compiled on a machine that
has X and a display.  If that means adding 22.5 MB to our tarball for
Cairo... maybe, maybe not.

I won't copy Matt's message here, but I appreciate the pointers to
exactly where these things are defined very much - without knowing
where to look, it would be a long slog.   Hopefully we'll have some
success!  Thanks for the replies, and for any other ideas.

Karl-Dieter