Re: [matplotlib-devel] Y axis scaling bug

[Paul B. <ba...@st...>]

John Hunter wrote:
>>>>>>"Fernando" == Fernando Perez <Fer...@co...> writes:
> 
> 
> 
>     Fernando> Well, I actually tried to see it but gv (Fedora Core 2)
>     Fernando> chokes on the file: CPU utilization goes to 100% after
>     Fernando> displaying the axes, labels, and a tiny bit of the
>     Fernando> graph.  I killed it after a while.
> 
> I had the same problem with ggv (but I converted it with ps2pdf and
> viewed it as pdf).  What are you using as a PS viewer Paul?

GGV (i.e. Gnome ghostview)

> One thing that concerns about embedding truetype fonts in PS figures
> is that they don't look very good in standard viewers (xdvi, ggv)
> though they seem to print fine, at least on the printers I've tried.
> It may be that the viewers don't have very good truetype rendering
> algorithms.

It might also be the standard fonts that we use.  In other words, there might be 
other truetype fonts that render better with freetype2.

> I'm on the fence about whether we should revert to the afm fonts for
> plain text in PS, and just use truetype for mathtext and if
> explicitly requested using a yet-to-be-determined mechanism.  These
> certainly look better in the PS viewers I've tried.  Of course the
> truetype fonts offer the same look and feel across backends, which is
> why I am on the fence.  Any opinions here?

I don't see a gain here, since PS output is mainly for printing where the fonts 
look fine.  Maybe we should invest more effort in a PDF backend, which displays 
better in a viewer and also does the conversion to PS.  Or switch to TTF that 
render better in a viewer, such as the core MS TT fonts.

>     Fernando> Are there known problems with the Postscript generated
>     Fernando> by matplotlib?  Can it produce EPS directly (better for
>     Fernando> publication)?
> 
> EPS: yes - just save as *.eps from just about any backend.
> 
> The only reported problem I've heard was a post from Flavio Coelho
> 
>   While on the same topic, I had some problems inserting matplotlib
>   generated PS plots into TeXMacs, although they open normally in gv,
>   for instance. have you have seen any compatibility issues for the PS
>   files and other PS viewing programs?  Running ps2ps on the
>   matplotlib PS files resolved the problem. However I wanted to use
>   TexMacs as a frontend to use matplotlib interactively...
> 
> Paul, so we could help narrow this problem with gv and your figure,
> could you try generating it with 0.60.2 (which uses AFM if I recall
> correctly) to see if it is related to the new font handling in PS?

I'll take a look at it.  However, I suspect the fonts are not the problem, since 
each font only increases the size of the PS file by about 60 kBs.  I suspect it 
is the size of the data and the rendering code that is causing the problem.

  -- Paul

-- 
Paul Barrett, PhD      Space Telescope Science Institute
Phone: 410-338-4475    ESS/Science Software Branch
FAX:   410-338-4767    Baltimore, MD 21218