plot issues

[Ethan Merritt]

On Friday 05 June 2009 11:12:52 Benjamin Lindner wrote:
> Ethan Merritt wrote:
> > On Friday 05 June 2009, Ben Abbott wrote:
> > 
> >>>> Petr, what are the benefits of the pdfcairo and pngcairo terminals  
> >>>> over the pdf and png terminals?
> > 
> > Aside from licensing issues for PDFLib, using cairo to generate the plots
> > allows antialiasing, transparency, and UTF-8 support.  
> 
> This may be a sutpid question, but what should a vector-based graphics 
> description support antialiasing for?

Ben asked about both pdfcairo and pngcairo.
The anti-aliasing is an issue for png, not for pdf.
Conversely, the transparency support is an issue for pdf but not for png.

> pdfcairo might be superior if you require transparency and UTF-8, 
> granted, but the quality of the generated output is disappointing 
> compared to pdf via postscript.
> I do a lot of image plots and found that the resulting file sizes with 
> the pdfcairo terminal are 4-8 times larger than a ps->pdf output. Also 
> you don't have good control over font selection, which is IMO a 
> knock-out criteria when doing high-quality plots for e.g. latex inclusion.

All I can say is that I have had the opposite experience.
Maybe that's because I work in a UTF environment and need support
for CJK character sets.  PostScript is basically hopeless for those.
There are some very fragile workarounds, but they are so installation-
specific that it doesn't work to build scripts or work flow around them.

For latex inclusion, ps2pdf or direct PDF generation should be exactly
the same, and subject to the same limitations of whatever converted
Computer Modern fonts you are using.  If that is a primary concern,
then using one of the latex-based terminals directly is a better bet.

	Ethan

-- 
Ethan A Merritt
Biomolecular Structure Center
University of Washington, Seattle 98195-7742