Re: [Matplotlib-users] How to mix maths & text in labels ?

[Darren D. <dd...@co...>]

Hi William,

On Thursday 02 June 2005 11:49 am, William Henney wrote:
> Hi list
>
> On Wed, 2005-06-01 at 13:25 -0500, John Hunter wrote:
> > >>>>> "Chris" =3D=3D Chris Barker <Chr...@no...> writes:
> >
> >     Chris> Wonderful! this is great news. How have you done it? Have
> >     Chris> you written a DVI driver? or do you use TeX and associated
> >     Chris> tools to create a bitmap and put that on the image? Or
> >     Chris> something else?
> >
> > For *Agg, we use tex + dvipng and load the output as a transparent,
> > anti-aliased raster, caching the dvipng output in ~/.tex.cache for
> > efficiency.  For PS, we use tex + dvips + psfrag + latex + a patched
> > ps2epsi.  The latter is cumbersome, but it works.  In an ideal world,
> > we would simply use tex + dvips but embedding the postscript fragments
> > generated by dvips in arbitrary locations on the figure, but this has
> > proved challenging.
>
> Have you looked at how PyX (http://pyx.sourceforge.net/) handles things?
> They have excellent support for tex/latex labels and it seems to be
> implemented in a much "cleaner" way than you describe above. As far as I
> can see, they run a single TeX job containing all the strings from the
> current plot (see the texrunner class in pyx/text.py) and then parse the
> dvi output themselves (see pyx/dvifile.py)
>
> > Having our own dvi parser would be a nice solution.  As you noted, the
> > format isn't too complicated, except for the font handling and the
> > fact that you need your own bytecode processing engine to extract the
> > information.  We're waiting until Robert Kern has another boring
> > experiment to site through for this one.
>
> Well, PyX is GPLed so I don't see why you couldn't adopt their DVI
> parser. One thing you need to bear in mind if you are using TeX to
> generate PS output is that the resultant files will probably be
> unacceptable to many scientific journals without further processing. The
> production staff generally try to open the PS files in Adobe Illustrator
> and this causes multiple problems with files generated both by PyX and
> by dvips.=20

Why is this?

> The solution is to convert all fonts to outlines before=20
> submission (and also make sure all bbox coords are +ve). You can do this
> with recent versions of ghostscript:
>
>  gs -dBATCH -dNOPAUSE -dSAFER -q -sDEVICE=3Depswrite -dEPSFitPage \
>     -sOutputFile=3Dnew.eps old.eps

Coincidentally, I was just addressing the use of gs's epswrite this morning=
 on=20
the matplotlib-devel list. Unfortunately, epswrite will yield a file that=20
does not render well on screen. Given the increasing popularity of online=20
publication, it seems this approach for generating eps files would not be=20
acceptable to scientific journals either.

>
> I suppose I should introduce myself since I haven't posted to this list
> before. I've been looking at various python scientific plotting packages
> for the last few months. I'm currently using gnuplot (supplemented by
> bash or python scripting) for interactive use and quick hacks, together
> with PyX for publication-quality output. Matplotlib looks very
> interesting since I think it could potentially replace both gnuplot and
> PyX. The features it seemed to be lacking the last time I looked in any
> detail (v 0.70) were
>
> 1. Good, flexible support for reading data from files

Could you give an example? In my experience, datafiles tend to get so=20
complicated that all of Matlabs tools were useless. I end up writing code=20
specific to every type that isnt as simple as a few comment lines that are=
=20
ignored followed by a delimited array of data.



=2D-=20
Darren S. Dale

Bard Hall
Department of Materials Science and Engineering
Cornell University
Ithaca, NY. 14850

dd...@co...
http://people.ccmr.cornell.edu/~dd55/