[R-sig-eco] Publication quality graphics in R

[T. Avery]

Phil's and others suggestions for publication-quality graphics are all 
good ones. I would like to point out that The GIMP (www.gimp.org) for 
raster images, applications based on Ghostscript/Ghostview/GSview 
(http://pages.cs.wisc.edu/~ghost/) or those apps themselves, or 
applications like PDFCreator/PDFtoolkit/PDFtkBuilder for postscript and 
PDF manipulation, and, finally, Inkscape (www.inkscape.org) for vector 
images, will do everything that the expensive cousins (Acrobat, 
Illustrator, Photoshop) will do and more. Plus most are crossplatform 
and open-source. All are free!

The main trick in graphics is to create the graphic at the size and 
resolution required for final publication. That way the journal does not 
have to resize/resample (at least not too much) and the chance of 
messing up the graphics is reduced. Remember that screen resolution is 
72 dpi (96 dpi in some cases) and that print graphics are generally done 
at 300 dpi so your working image on screen will be 300/72=4.2 x the 
print size (at proper 300 dpi) - 72 or 96 really doesn't matter as it is 
the final graphic size/resolution that is key. Any lossy format (jpg, 
gif) will reduce quality because those formats use an algorithm to 'fill 
in' colour space etc.. The result is blurry images since a black line on 
a white background will have steps of grey produced by the algorithm 
(just zoom in to pixel size to see what I mean). Choose a lossless 
format (tiff, png), or vector formats (pdf, ps, eps) that are also 
lossless (by virtue of being vectorized) to guarantee that what you 
intend is seen. And, finally, use formats that are 
crossplatform/universal so that everyone can get along. Remember that 
eps embeds a tiff image of low quality for viewing/positioning purposes 
when using a layout program so don't get fooled into thinking that is 
your image!

It really bugs me when journals want everything in a M$ Word document or 
graphics in Corel Draw or Illustrator especially when they will 
(usually) be using a higher quality layout application like Quark for 
publication which (usually) work in postscript format. Besides, some of 
us use Linux/Mac and better apps such as OpenOffice.org.

cheers,
trevor avery
biology
Acadia univiersity