Re: plot issues -> favor pdfcairo

[Benjamin Lindner]

Ben Abbott wrote:
> On Jun 6, 2009, at 10:38 AM, Ben Abbott wrote:
>
> > On Jun 6, 2009, at 7:49 AM, Benjamin Lindner wrote:
> >
> > > Ben Abbott wrote:
> > > > On Jun 5, 2009, at 4:08 PM, Ethan Merritt wrote:
> > > > > 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
> > > > It doesn't appear to me that there is one solution that is preferred 
> > > > over the other in all cases.
> > > > I'll propose the following, and encourage all to comment.
> > > > -----------
> > > > 1) if "pdfcairo" is present => use "set term pdfcairo ..."
> > > > 2) if "pdf" is present => use "set term pdf ..."
> > > > 3) if neither => use "set term postscript ..." and then convert 
> > > > using ghostscript
> > > > -----------
> > >
> > > Sounds very reasonable to me.
> > >
> > > > Although I'm a big LaTeX user, I elevated pdfcairo over pdf for the 
> > > > transparency feature.
> > > > Similarly for png
> > > > -----------
> > > > 1) if "pngcairo" is present => use "set term pngcairo ..."
> > > > 2) if "png" is present => use "set term png ..."
> > > > 3) if neither => use "set term postscript eps ..." and then convert 
> > > > using ghostscript
> > > > -----------
> > >
> > > same as above
> > >
> > > > For LaTeX, I will soon be adding support for the Lua/TikZ terminal. 
> > > > Its rendering is a bit slow, but produces excellent results for both 
> > > > latex and pdflatex.
> > > > The solutions above will only work well for gnuplot 4.3+. Prior to 
> > > > that the variable GPVAL_TERMINALS does not exist, and octave has no 
> > > > manner to check for the existence of specific terminals.
> > >
> > > For windows platform this is OK, since a working console application 
> > > is only possible with 4.3+
> > > Also interactive zooming with piped gnuplot works only with 4.3+
> > >
> > > benjamin
> >
> > Great!
> >
> > I've attached a changeset for the pdf part. It is combined with a 
> > changeset for forcing mono rendering (there is some problem with 
> > rgb2gray that has delayed me in pushing that change).
> >
> > In any event, I'd appreciated confirmation form linux and window's 
> > users that this chageset works correctly.
> >
> > Ben
>
> I've rolled up all the changesets for these plot issues. The attached 
> must be applied to the current sources. With this change applied, the 
> print command will favor the cairo terminals and will properly render a 
> gray-scale image when the -mono option is specified.
>
> I'd appreciate some testing to make sure there are no surprises.
>
> I also  noticed we've been on bug list. I've moved this over to the 
> maintainers list (I should have done that many emails ago).

Hmm, I tried to import your changeset, but it fails for all hunks.
My tip is 9305:52b4d82e5b4f from http://www.octave.org/hg/octave

benjamin