matplotlib-devel Mailing List for matplotlib (Page 4)

Nothing much in the regards of the functionality.
It only provides a way to use custom backends with "savefig", which I
think is more convenient for interactive use. For example, with the
ps_cmyk backend that I'm playing with, the only thing that I  need to
do is to import the module (ps_cmyk) and call

savefig("test.eps", format="eps_cmyk")

And all other (interactive) work flow is not affected by the use of
the custome backend.
In non-interactive mode where a user explicitly calls
"matplotlib.use", there is no need to register a backend.

Regards,

-JJ



On Wed, Feb 3, 2010 at 4:15 PM, Ryan May <rm...@gm...> wrote:
> On Wed, Feb 3, 2010 at 2:01 PM, Jae-Joon Lee <lee...@gm...> wrote:
>> Dear all,
>>
>> I just committed a small change that enables a user to register a
>> custom backend that will be used with "savefig".
>> For example,
>>
>> import matplotlib.backend_bases
>> from matplotlib.backends.backend_ps import FigureCanvasPS, RendererPS
>>
>> class RendererPSCustom(RendererPS):
>>    def draw_path(self, gc, path, transform, rgbFace=None):
>>        print "custom draw path"
>>        RendererPS.draw_path(self, gc, path, transform, rgbFace)
>>
>> class FigureCanvasPSCustom(FigureCanvasPS):
>>    _renderer_class = RendererPSCustom
>>
>>    def print_eps_custom(self, outfile, *args, **kwargs):
>>        print "Using Custome backend"
>>        return self._print_ps(outfile, 'eps', *args, **kwargs)
>>
>>
>> matplotlib.backend_bases.register_backend("eps_custom", FigureCanvasPSCustom)
>>
>> plt.plot([1,2,3])
>> plt.savefig("a.eps", format="eps_custom") # this will save the file
>> using  backend_ps_cmyk
>>
>>
>> The api may need some cleanups or modifications, and any suggestion
>> will be welcomed.
>>
>> Also committed is a some refactoring of ps backend but the change
>> should be quite transparent.
>
> I like it.  Out of curiosity, is there anything that this approach
> brings (other than simplicity) that isn't already covered by the
> support for:
>
> matplotlib.use('module:://')
>
> ?
>
> Ryan
>
> --
> Ryan May
> Graduate Research Assistant
> School of Meteorology
> University of Oklahoma
>

On Wed, Feb 3, 2010 at 2:01 PM, Jae-Joon Lee <lee...@gm...> wrote:
> Dear all,
>
> I just committed a small change that enables a user to register a
> custom backend that will be used with "savefig".
> For example,
>
> import matplotlib.backend_bases
> from matplotlib.backends.backend_ps import FigureCanvasPS, RendererPS
>
> class RendererPSCustom(RendererPS):
>    def draw_path(self, gc, path, transform, rgbFace=None):
>        print "custom draw path"
>        RendererPS.draw_path(self, gc, path, transform, rgbFace)
>
> class FigureCanvasPSCustom(FigureCanvasPS):
>    _renderer_class = RendererPSCustom
>
>    def print_eps_custom(self, outfile, *args, **kwargs):
>        print "Using Custome backend"
>        return self._print_ps(outfile, 'eps', *args, **kwargs)
>
>
> matplotlib.backend_bases.register_backend("eps_custom", FigureCanvasPSCustom)
>
> plt.plot([1,2,3])
> plt.savefig("a.eps", format="eps_custom") # this will save the file
> using  backend_ps_cmyk
>
>
> The api may need some cleanups or modifications, and any suggestion
> will be welcomed.
>
> Also committed is a some refactoring of ps backend but the change
> should be quite transparent.

I like it.  Out of curiosity, is there anything that this approach
brings (other than simplicity) that isn't already covered by the
support for:

matplotlib.use('module:://')

?

Ryan

-- 
Ryan May
Graduate Research Assistant
School of Meteorology
University of Oklahoma

I'm experimenting with a customized ps backend that saves images in
cmyk colorspace.
It simply converts the rgb image to cmyk (using lcms), and nothing
more (i.e., it does not embed the icc profile inside the eps file).
While I don't see practical usefulness of this other than for a
previewing purpose, give it a try if you're interested (the current
svn matplotlib is required).
Any comment of suggestion will be welcomed.

http://github.com/leejjoon/mpl_ps_cmyk

Regards,

-JJ

Dear all,

I just committed a small change that enables a user to register a
custom backend that will be used with "savefig".
For example,

import matplotlib.backend_bases
from matplotlib.backends.backend_ps import FigureCanvasPS, RendererPS

class RendererPSCustom(RendererPS):
    def draw_path(self, gc, path, transform, rgbFace=None):
        print "custom draw path"
        RendererPS.draw_path(self, gc, path, transform, rgbFace)

class FigureCanvasPSCustom(FigureCanvasPS):
    _renderer_class = RendererPSCustom

    def print_eps_custom(self, outfile, *args, **kwargs):
        print "Using Custome backend"
        return self._print_ps(outfile, 'eps', *args, **kwargs)


matplotlib.backend_bases.register_backend("eps_custom", FigureCanvasPSCustom)

plt.plot([1,2,3])
plt.savefig("a.eps", format="eps_custom") # this will save the file
using  backend_ps_cmyk


The api may need some cleanups or modifications, and any suggestion
will be welcomed.

Also committed is a some refactoring of ps backend but the change
should be quite transparent.

Regards,

-JJ

I can't seem to reproduce this on a 32-bit RHEL4 machine with:

python-2.5.4
matplotlib-0.99.1.2
GNU ghostscript 7.07

and viewed with any of:

Adobe Reader 8.1.7
xpdf 3.00
ggv 2.8.0
(sorry no evince on RHEL4)

What versions of these tools are you running?  Do you have any 
customizations in your matplotlibrc file?  Can you send me (off-list) 
the ps/eps and pdf files in question?

Mike

David J. Raymond wrote:
> I'm running v0.99.1.2 on Debian Linux, 32 bit Intel.  A colorbar on
> the right with negative labels produces postscript-eps output which
> displays ok with gv or evince.  But when conversion of the ps/eps file
> to pdf is made, the negative labels get replaced by dashes when the
> pdf is viewed by xpdf or evince.  A variety of pdf conversion methods
> (ps2pdf, pdflatex) were used, all with the same result.  I am
> including a simple sample python script which creates a graphic with
> the problem:
>
> ---------------------------------------------------------------------
>
> #!/usr/bin/python
> from numpy import *
> import matplotlib.pyplot as plt
>
> # this demos a bug in the eps output
>
> x = linspace(0,6,13)
> y = linspace(0,3,7)
> (X,Y) = meshgrid(x,y)
> a = 3.5*sin(X)*sin(Y)
>
> c = plt.contourf(x,y,a)
> b = plt.colorbar(c, orientation = 'vertical')
> lx = plt.xlabel('x')
> ly = plt.ylabel('y')
> ax = plt.axis([0,6,0,3])
>
> plt.show()
>
> ---------------------------------------------------------------------
>
> Xpdf outputs the following error messages:
> Error: Bad bounding box in Type 3 glyph
> Error: Missing or bad Type3 CharProc entry
> Error: Bad bounding box in Type 3 glyph
> Error: Missing or bad Type3 CharProc entry
> Error: Bad bounding box in Type 3 glyph
> Error: Missing or bad Type3 CharProc entry
> Error: Bad bounding box in Type 3 glyph
> Error: Missing or bad Type3 CharProc entry
> Error: Bad bounding box in Type 3 glyph
> Error: Missing or bad Type3 CharProc entry
> Error: Bad bounding box in Type 3 glyph
> Error: Missing or bad Type3 CharProc entry
> Error: Bad bounding box in Type 3 glyph
> Error: Missing or bad Type3 CharProc entry
> Error: Bad bounding box in Type 3 glyph
> Error: Missing or bad Type3 CharProc entry
>
> These don't appear if there are no negative numbers in the
> colorbar scale.
>
> Dave Raymond
>
> PS -- I haven't filed a bug report because I haven't been able
> to figure out the Source Forge bug reporting system yet.
>
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>   

-- 
Michael Droettboom
Science Software Branch
Operations and Engineering Division
Space Telescope Science Institute
Operated by AURA for NASA

I'm running v0.99.1.2 on Debian Linux, 32 bit Intel.  A colorbar on
the right with negative labels produces postscript-eps output which
displays ok with gv or evince.  But when conversion of the ps/eps file
to pdf is made, the negative labels get replaced by dashes when the
pdf is viewed by xpdf or evince.  A variety of pdf conversion methods
(ps2pdf, pdflatex) were used, all with the same result.  I am
including a simple sample python script which creates a graphic with
the problem:

---------------------------------------------------------------------

#!/usr/bin/python
from numpy import *
import matplotlib.pyplot as plt

# this demos a bug in the eps output

x = linspace(0,6,13)
y = linspace(0,3,7)
(X,Y) = meshgrid(x,y)
a = 3.5*sin(X)*sin(Y)

c = plt.contourf(x,y,a)
b = plt.colorbar(c, orientation = 'vertical')
lx = plt.xlabel('x')
ly = plt.ylabel('y')
ax = plt.axis([0,6,0,3])

plt.show()

---------------------------------------------------------------------

Xpdf outputs the following error messages:
Error: Bad bounding box in Type 3 glyph
Error: Missing or bad Type3 CharProc entry
Error: Bad bounding box in Type 3 glyph
Error: Missing or bad Type3 CharProc entry
Error: Bad bounding box in Type 3 glyph
Error: Missing or bad Type3 CharProc entry
Error: Bad bounding box in Type 3 glyph
Error: Missing or bad Type3 CharProc entry
Error: Bad bounding box in Type 3 glyph
Error: Missing or bad Type3 CharProc entry
Error: Bad bounding box in Type 3 glyph
Error: Missing or bad Type3 CharProc entry
Error: Bad bounding box in Type 3 glyph
Error: Missing or bad Type3 CharProc entry
Error: Bad bounding box in Type 3 glyph
Error: Missing or bad Type3 CharProc entry

These don't appear if there are no negative numbers in the
colorbar scale.

Dave Raymond

PS -- I haven't filed a bug report because I haven't been able
to figure out the Source Forge bug reporting system yet.