matplotlib

>>>>> "Nicholas" == Nicholas Young <subs@...> writes:

    Nicholas> Hi, I regularly use matplotlib on lots of systems I
    Nicholas> don't have root access to.  On most of these
    Nicholas> installation of gs 8.15 is quite problematic (and buggy)
    Nicholas> and as I result using TeX with matplotlib is
    Nicholas> impractical.  Additionally as all of the printers I have
    Nicholas> access to are HP made the use of embedded truetype fonts
    Nicholas> is also problematic.  The combination of these two
    Nicholas> problems has made it difficult to use mpl for anything I
    Nicholas> need to print and for which I need mathtext.

Hi this looks very nice!  I have to run now but I'll give you a quick
tip.  kerning controls the inter-letter spacing, and your Fonts class
has to override "get_kern"; the base class always returns 0

    def get_kern(self, font, symleft, symright, fontsize, dpi):
        """
        Get the kerning distance for font between symleft and symright.

        font is one of tt, it, rm, cal or None

        sym is a single symbol(alphanum, punct) or a special symbol
        like \sigma.

        """
        return 0


For an afm class instance, you can call get_kern_distance to get the
kerning distance between two characters.


    >>> from afm import AFM
    >>> fh = file('ptmr8a.afm')
    >>> afm = AFM(fh)
    >>> afm.get_kern_dist('A', 'y')
    -92.0

and if I recall correctly this has to be corrected by a factor of
1000.

JDH

On Wed, 2005-10-19 at 12:08 -0500, John Hunter wrote:
> Hi this looks very nice!  I have to run now but I'll give you a quick
> tip.  kerning controls the inter-letter spacing, and your Fonts class
> has to override "get_kern"; the base class always returns 0

I had missed this function - but as far as I can see it isn't actually
called in the majority of cases (only where set_font is called on the
parent GroupElement - which doesn't always happen in any of the common
cases I've tried).  Am I missing something?

Nick

>>>>> "Nicholas" == Nicholas Young <subs@...> writes:

    Nicholas> On Wed, 2005-10-19 at 12:08 -0500, John Hunter wrote:
    >> Hi this looks very nice!  I have to run now but I'll give you a
    >> quick tip.  kerning controls the inter-letter spacing, and your
    >> Fonts class has to override "get_kern"; the base class always
    >> returns 0

    Nicholas> I had missed this function - but as far as I can see it
    Nicholas> isn't actually called in the majority of cases (only
    Nicholas> where set_font is called on the parent GroupElement -
    Nicholas> which doesn't always happen in any of the common cases
    Nicholas> I've tried).  Am I missing something?

The Group element is the only place kerning is set, but groups are the
right place.  Eg \rm{hi mom} is a group.  I just took a look and
noticed I commented out the place where the kern is set

    def advance(self):
        'get the horiz advance'
        return self.metrics.advance # how to handle cm units?+ self.kern*self.widthm

It looks like I was a bit confused about how to best include the
kerning information, and was experimenting by treating it as a
fraction of the width of an "m".  You may want to try some
alternatives.  But this is where you would start hacking.

JDH

On Wed, 2005-10-19 at 15:28 -0500, John Hunter wrote:
> It looks like I was a bit confused about how to best include the
> kerning information, and was experimenting by treating it as a
> fraction of the width of an "m".  You may want to try some
> alternatives.  But this is where you would start hacking.

I've made some improvements and I think the result looks as good as it's
going to using the Symbol font and without a suitable font for \cal; a
revised patch is attached.  In the patch I've refactored the kerning in
mathtext.py and removed all kerning information from TrueType the font
classes (as it wasn't being used anyway) by renaming the relevant
get_kern functions.

Nick

>>>>> "Nicholas" == Nicholas Young <subs@...> writes:

    Nicholas> Hi, I regularly use matplotlib on lots of systems I
    Nicholas> don't have root access to.  On most of these
    Nicholas> installation of gs 8.15 is quite problematic (and buggy)
    Nicholas> and as I result using TeX with matplotlib is
    Nicholas> impractical.  Additionally as all of the printers I have
    Nicholas> access to are HP made the use of embedded truetype fonts
    Nicholas> is also problematic.  The combination of these two
    Nicholas> problems has made it difficult to use mpl for anything I
    Nicholas> need to print and for which I need mathtext.

    Nicholas> As a solution I've patched the mathtext library and
    Nicholas> backend_ps in order to support mathtext based upon the
    Nicholas> standard postscript Symbol font when ps.usetex = True.
    Nicholas> A function patch to CVS is attached.

Thanks Nick -- just committed this to CVS so it will be in the next
release

Checking in lib/matplotlib/mathtext.py;
/cvsroot/matplotlib/matplotlib/lib/matplotlib/mathtext.py,v  <--
matht\
ext.py
new revision: 1.21; previous revision: 1.20
done
Checking in lib/matplotlib/backends/backend_ps.py;
/cvsroot/matplotlib/matplotlib/lib/matplotlib/backends/backend_ps.py,v
\
 <--  backend_ps.py
new revision: 1.69; previous revision: 1.68
done


JDH

I've made a small alteration to my code for AFM mathtext to show digits
and brackets () in the roman rather than the italic font, as is normal
in mathtext.  The patch is attached.

Nicholas

>>>>> "Nicholas" == Nicholas Young <subs@...> writes:

    Nicholas> I've made a small alteration to my code for AFM mathtext
    Nicholas> to show digits and brackets () in the roman rather than
    Nicholas> the italic font, as is normal in mathtext.  The patch is
    Nicholas> attached.

Thanks Nicholas, changes in CVS.
JDH