[R] Getting R to emit an image file as a pipe or Base64 strea m: Mac OSX 10.3 - R 2.0.1

[Liaw, Andy]

> From: Yuandan Zhang
> 
> If you want to call R from perl, why don't you do a simple 
> system call like:
> 
> $callR="/usr/loca/bin/R CMD BATCH plotscript.R";
> system ($callR);
> 
> It is not necessary to start X display if anything can be 
> done in background

But the problem is jpeg()/png() are not available unless an X display is
available to the R process (one of the FAQs).  

Andy 
 
> On Fri, 3 Dec 2004 12:07:24 +1100 (EST)
> "Thuan-Jin Kee" <kee at wehi.EDU.AU> wrote:
> 
> > Hi All,
> > 
> > Anybody know how to make R emit base64 encoded text in some 
> way that perl
> > can grab it, instead of planting a file on your harddrive 
> when calling
> > JPEG or PNG?
> > I've managed to get these scripts to work and put a file on 
> the harddisk
> > 
> > #!/usr/bin/perl -Wall
> > # by jin kee. a simple script to demonstrate
> > # the needed steps to get R to emit a jpeg.
> > 
> > use strict;
> > 
> > my($callR, $callRold);
> > 
> > # need to start X if is isn't already started.
> > `open /Applications/Utilities/X11.app`;
> > 
> > 
> > #need to get let the R program know where to look
> > #for the display immediately before calling
> > #the R executible.
> > $callR =<<MARKER;
> > DISPLAY=:0.0; export DISPLAY;
> > /usr/bin/R --vanilla <plotscript.R;
> > MARKER
> > 
> > system($callR);
> > 
> > # end script
> > 
> > #!/usr/bin/R
> > peg("~/Desktop/test.jpg");
> > plot(rnorm(100));
> > dev.off();
> > q(save = "no");
> > 
> > 
> > My sysadmin says that the apache user can't write to the disk due to
> > security policy, so he wants to know if I can emit the jpeg 
> as a base64
> > stream and embedd it into the dynamically generated tag 
> using a DATA tag
> > to inline the image.
> > 
> > http://www.elf.org/essay/inline-image.html
> > 
> > http://www.faqs.org/rfcs/rfc2397.html
> > 
> > i've tried searching the R-project.org site and 
> help.search() and no luck.
> > 
> > Yours
> > Jin
> > 
> > ______________________________________________
> > R-help at 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
> 
> 
> -- 
> 
> --
> Yuandan 
> Zhang, PhD
> 
> Animal Genetics and Breeding Unit
> The University of New England
> Armidale, NSW, Australia, 2351
> 
> E-mail:   yzhang4 at metz.une.edu.au
> Phone:    (61) 02 6773 3786
> Fax:      (61) 02 6773 3266
> http://agbu.une.edu.au
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   AGBU is a joint venture of NSW Primary Industries 
>   and The University of New England to undertake 
>   genetic R&D for Australia's Livestock Industries           
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> ______________________________________________
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> PLEASE do read the posting guide! 
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> 
>