matplotlib-users Mailing List for matplotlib

In article <E87...@cs...>,
 belinda thom <bt...@cs...> wrote:

> Hi again,
> 
> At http://matplotlib.sourceforge.net/installing.html under topic OS X:
> 
>    "All of the backends run on OS X. Chris Barker has built a binary  
> package (fink users see below) for matplotlib which is hosted on  
> pythonmac, and works with Agg, Wx and Tk; see the step-by-step  
> instructions kindly provided by Michael Tobis."
> 
> note that the step-by-step link leads to:
> 
>    Under revision. Please come back soon.

That is indeed outdated (Charlie Moad has done most of the recent binary 
builds, though I got in first on a few). One source of "how to build" is:
Building Matplotlib for MacOS 
<http://www.astro.washington.edu/rowen/BuildingMatplotlibForMac.html>

-- Russell

Robert Cimrman wrote:
[...]
> What could be done, though, is to raise an exception explaining that 
> sparse matrices and the image mode don't like each other; as it is, the 
> function spy3 just dies on asarray (should be st. like asarray( 
> Z.todense() ))

(I think it would be Z.toarray().)

Good point.  Alternatives would be to automatically switch it to plot 
mode, with a warning, or to automatically convert it.  Probably the 
former is the better of these two, and maybe your originally suggested 
exception is best of all.  What do you think?

Eric

Yannick Copin wrote:
> Hi,
> 
> Eric Firing wrote:
>>> from pylab import *
>>> X, Y = meshgrid(linspace(-3,3,11),linspace(-3,3,11))
>>> Z = randn(*X.shape)
>>> lev = linspace(Z.min(),Z.max(),11)[1:-1]
>>> contourf(X,Y,Z, lev, extend='both')
>>> contour(X,Y,Z, lev, colors='k')
>>> show()
>>
>> Now, you may be wondering why we can't simply use the boundary of the 
>> filled regions for the lines as well, to guarantee they are the same. 
>> The reason is that filled contour boundaries include cuts connecting 
>> inner and outer contours, and also inner boundaries (edges of masked 
>> regions--except when affected by a bug) and the outer boundaries of 
>> the domain).  It might be possible to simply exclude those line 
>> segments from the line contours, but it is not clear to me that the 
>> effort would be well-spent.
> 
> OK, thanks for the explanations. I was using this dual approach 
> contourf+contour to emphasize the contours from contourf. So is there a 
> direct way to set the linewidth and linecolor (and linestyle?) of 
> contours from contourf? (I suspect not, according to contourf 
> documentation:
> 
>     contourf differs from the Matlab (TM) version in that it does not
>         draw the polygon edges, because the contouring engine yields
>         simply connected regions with branch cuts.  To draw the edges,
>         add line contours with calls to contour.
> 
> )
> 

You could turn on coloring of the edges, but I don't think you would 
like the result because the edges would include the boundary lines and 
the cut lines.

The ContourSet object returned by contour and contourf has a 
.collections attribute.  For contourf it is a list of PolyCollections, 
and you can set their attributes.


>> I think that the differences illustrated in your example will occur 
>> almost entirely in pathologically ambiguous cases, but it is also 
> 
> Not necessarily pathological cases, just noisy data :-/ (I agree my 
> randn-based example was a bit extreme!)

You might be able to avoid the problem most of the time by using some 
gridding routine, preferably something that uses a bit of curvature, to 
double the number of points in each dimension.  I haven't tried it, but 
I suspect that this would turn even a very noisy field into something 
that would be contoured the same by contour and contourf.

> 
> Cheers.

Steve Schmerler a =E9crit :
> Darren Dale wrote:
>  =20
>> On Monday 11 December 2006 09:59, Nicolas Champavert wrote:
>>    =20
>>> Steve Schmerler a =E9crit :
>>>      =20
>>>> Nicolas Champavert wrote:
>>>>        =20
>>>>> Hello,
>>>>>
>>>>>   I have some problems when trying to save a figure with usetex=3DT=
rue.
>>>>> Sometimes, it is not possible to save the figure when trying to put=
 an
>>>>> xlabel with LaTeX inside.
>>>>> It works with pylab.xlabel('M$_\odot$') but not with
>>>>> pylab.xlabel('10$^3$ M$_\odot$') (see below). Do you know why ?
>>>>>          =20
>>>> Works fine here, with and w/o raw strings.
>>>>        =20
>> [...]
>>    =20
>>> I had matplotlib revision 2835. I made an upgrade. Now I have revisio=
n
>>> 2905. I still have problem but it is very strange:
>>> - when I plot [0,1] with xlabel(r'(10$^3$ M$_\odot$)'), it works.
>>> - when I plot [1,2] with xlabel(r'Upper mass for the IMF (10$^3$
>>> M$_\odot$)'), it works.
>>> - but it doesn't work if I plot [0,1] with xlabel(r'Upper mass for th=
e
>>> IMF (10$^3$ M$_\odot$)')...
>>>      =20
>> It sounds like an issue with one of the dependencies, probably ghostsc=
ript. I=20
>> have matplotlib-0.87.7, svn revision 2905, and gpl-ghostscript-8.54. I=
 can=20
>> not reproduce the problem here.
>>
>>    =20
>
> I seem to be running ESP Ghostscript 8.15.3 (this is what 'gs --version=
'=20
> and 'apt-cache show gs' tell me). All the examples work fine here ...
>
>  =20
I had Ghostscript 8.15.3 too. I have made an update to ghostscript 8.54=20
and now it works.

Nicolas

Darren Dale wrote:
> On Monday 11 December 2006 09:59, Nicolas Champavert wrote:
>> Steve Schmerler a écrit :
>>> Nicolas Champavert wrote:
>>>> Hello,
>>>>
>>>>   I have some problems when trying to save a figure with usetex=True.
>>>> Sometimes, it is not possible to save the figure when trying to put an
>>>> xlabel with LaTeX inside.
>>>> It works with pylab.xlabel('M$_\odot$') but not with
>>>> pylab.xlabel('10$^3$ M$_\odot$') (see below). Do you know why ?
>>> Works fine here, with and w/o raw strings.
> [...]
>> I had matplotlib revision 2835. I made an upgrade. Now I have revision
>> 2905. I still have problem but it is very strange:
>> - when I plot [0,1] with xlabel(r'(10$^3$ M$_\odot$)'), it works.
>> - when I plot [1,2] with xlabel(r'Upper mass for the IMF (10$^3$
>> M$_\odot$)'), it works.
>> - but it doesn't work if I plot [0,1] with xlabel(r'Upper mass for the
>> IMF (10$^3$ M$_\odot$)')...
> 
> It sounds like an issue with one of the dependencies, probably ghostscript. I 
> have matplotlib-0.87.7, svn revision 2905, and gpl-ghostscript-8.54. I can 
> not reproduce the problem here.
> 

I seem to be running ESP Ghostscript 8.15.3 (this is what 'gs --version' 
and 'apt-cache show gs' tell me). All the examples work fine here ...

-- 
cheers,
steve

Random number generation is the art of producing pure gibberish as 
quickly as possible.

On Monday 11 December 2006 09:59, Nicolas Champavert wrote:
> Steve Schmerler a =E9crit :
> > Nicolas Champavert wrote:
> >> Hello,
> >>
> >>   I have some problems when trying to save a figure with usetex=3DTrue.
> >> Sometimes, it is not possible to save the figure when trying to put an
> >> xlabel with LaTeX inside.
> >> It works with pylab.xlabel('M$_\odot$') but not with
> >> pylab.xlabel('10$^3$ M$_\odot$') (see below). Do you know why ?
> >
> > Works fine here, with and w/o raw strings.
[...]
>
> I had matplotlib revision 2835. I made an upgrade. Now I have revision
> 2905. I still have problem but it is very strange:
> - when I plot [0,1] with xlabel(r'(10$^3$ M$_\odot$)'), it works.
> - when I plot [1,2] with xlabel(r'Upper mass for the IMF (10$^3$
> M$_\odot$)'), it works.
> - but it doesn't work if I plot [0,1] with xlabel(r'Upper mass for the
> IMF (10$^3$ M$_\odot$)')...

It sounds like an issue with one of the dependencies, probably ghostscript.=
 I=20
have matplotlib-0.87.7, svn revision 2905, and gpl-ghostscript-8.54. I can=
=20
not reproduce the problem here.

Darren

No the '\' is not the problem. \odot is a LaTeX command. I still have=20
the problem if I don't use it (see below with only pylab.xlabel(r'Upper=20
mass for the IMF (10$^3$)')) and \\odot writes 'odot' and doesn't write=20
the 'odot' symbol.


Gary Ruben a =E9crit :
> I haven't tried it, but my guess is the '\' character is the problem.
>
> > pylab.xlabel('10$^3$ M$_\odot$')
>
> Try
> pylab.xlabel(r'10$^3$ M$_\odot$')
>              ^
>              Add raw string marker.
>
> or maybe
> pylab.xlabel('10$^3$ M$_\\odot$')
>
> Gary R.
>
> Nicolas Champavert wrote:
>> Hello,
>>
>>   I have some problems when trying to save a figure with usetex=3DTrue=
.=20
>> Sometimes, it is not possible to save the figure when trying to put=20
>> an xlabel with LaTeX inside.
>> It works with pylab.xlabel('M$_\odot$') but not with=20
>> pylab.xlabel('10$^3$ M$_\odot$') (see below). Do you know why ?
>

In [1]:import matplotlib

In [2]:import pylab

In [3]:matplotlib.__version__
Out[3]:'0.87.7'

In [4]:matplotlib.__revision__
Out[4]:'$Revision: 2905 $'

In [5]:matplotlib.rc('text',usetex=3DTrue)

In [6]:pylab.plot([0,1])
Out[6]:[<matplotlib.lines.Line2D instance at 0xb67dde4c>]

In [7]:pylab.xlabel(r'Upper mass for the IMF (10$^3$)')
Out[7]:<matplotlib.text.Text instance at 0xb693d62c>

In [8]:pylab.savefig('test.eps')
sh: line 1: 19944 Erreur de segmentation  gs -dBATCH -dNOPAUSE -r6000=20
-sDEVICE=3Dpswrite -sPAPERSIZE=3Dletter=20
-sOutputFile=3D"/tmp/098f6bcd4621d373cade4e832627b4f6.ps"=20
"/tmp/098f6bcd4621d373cade4e832627b4f6"=20
 >"/tmp/098f6bcd4621d373cade4e832627b4f6.output"
-------------------------------------------------------------------------=
--
exceptions.RuntimeError                              Traceback (most=20
recent call last)

/home/champavert/<ipython console>

/usr/local/lib/python2.4/site-packages/matplotlib/pylab.py in=20
savefig(*args, **kwargs)
    811 def savefig(*args, **kwargs):
    812     fig =3D gcf()
--> 813     return fig.savefig(*args, **kwargs)
    814 if Figure.savefig.__doc__ is not None:
    815     savefig.__doc__ =3D _shift_string(Figure.savefig.__doc__)

/usr/local/lib/python2.4/site-packages/matplotlib/figure.py in=20
savefig(self, *args, **kwargs)
    685                 kwargs[key] =3D rcParams['savefig.%s'%key]
    686
--> 687         self.canvas.print_figure(*args, **kwargs)
    688
    689     def colorbar(self, mappable, cax=3DNone, **kw):

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_tkagg.=
py=20
in print_figure(self, filename, dpi, facecolor, edgecolor, orientation,=20
**kwargs)
    184         if dpi is None: dpi =3D rcParams['savefig.dpi']
    185         agg =3D self.switch_backends(FigureCanvasAgg)
--> 186         agg.print_figure(filename, dpi, facecolor, edgecolor,=20
orientation,
    187                          **kwargs)
    188         self.figure.set_canvas(self)

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_agg.py=
=20
in print_figure(self, filename, dpi, facecolor, edgecolor, orientation,=20
**kwargs)
    486                 ps =3D self.switch_backends(FigureCanvasPS)
    487                 ps.print_figure(filename, dpi, facecolor, edgecol=
or,
--> 488                                 orientation, **kwargs)
    489             elif ext.find('pdf')>=3D0:
    490                 from backend_pdf import FigureCanvasPdf

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_ps.py=20
in print_figure(self, outfile, dpi, facecolor, edgecolor, orientation,=20
papertype)
   1009             # Let's keep the usetex stuff seperate from the=20
generic postscript
   1010             self._print_figure_tex(outfile, dpi, facecolor,=20
edgecolor,
-> 1011                                    orientation, papertype)
   1012         else:
   1013             if  isinstance(outfile, file):

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_ps.py=20
in _print_figure_tex(self, outfile, dpi, facecolor, edgecolor,=20
orientation, papertype)
   1243         elif rcParams['text.usetex']:
   1244             if False: pass # for debugging
-> 1245             else: gs_distill(tmpfile, ext=3D=3D'.eps',=20
ptype=3Dpapertype, bbox=3Dbbox)
   1246
   1247         if  isinstance(outfile, file):

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_ps.py=20
in gs_distill(tmpfile, eps, ptype, bbox)
   1341     exit_status =3D os.system(command)
   1342     fh =3D file(outfile)
-> 1343     if exit_status: raise RuntimeError('ghostscript was not able=20
to process \
   1344 your image.\nHere is the full report generated by=20
ghostscript:\n\n' + fh.read())
   1345     else: verbose.report(fh.read(), 'debug')

RuntimeError: ghostscript was not able to process your image.
Here is the full report generated by ghostscript:

ESP Ghostscript 8.15 (2006-04-19)
Copyright (C) 2004 artofcode LLC, Benicia, CA.  All rights reserved.
This software comes with NO WARRANTY: see the file COPYING for details.

Steve Schmerler a =E9crit :
> Nicolas Champavert wrote:
>  =20
>> Hello,
>>
>>   I have some problems when trying to save a figure with usetex=3DTrue=
.=20
>> Sometimes, it is not possible to save the figure when trying to put an=
=20
>> xlabel with LaTeX inside.
>> It works with pylab.xlabel('M$_\odot$') but not with=20
>> pylab.xlabel('10$^3$ M$_\odot$') (see below). Do you know why ?
>>
>>    =20
>
>
> Works fine here, with and w/o raw strings.
>
> In [75]: rcParams['text.usetex']=3DTrue
>
> In [76]: plot([1,2,3])
> Out[76]: [<matplotlib.lines.Line2D instance at 0xa0db754c>]
>
> In [77]: xlabel('10$^3$ M$_\odot$')
> Out[77]: <matplotlib.text.Text instance at 0xa0daea2c>
>
> In [78]: savefig('test.eps')
>
> In [79]: matplotlib.__version__
> Out[79]: '0.87.7'
>
> In [80]: matplotlib.__revision__
> Out[80]: '$Revision: 2835 $'
>
>
> Maybe you need to upgrade, but that's just a guess.
>  =20
I had matplotlib revision 2835. I made an upgrade. Now I have revision 29=
05.
I still have problem but it is very strange:
- when I plot [0,1] with xlabel(r'(10$^3$ M$_\odot$)'), it works.
- when I plot [1,2] with xlabel(r'Upper mass for the IMF (10$^3$=20
M$_\odot$)'), it works.
- but it doesn't work if I plot [0,1] with xlabel(r'Upper mass for the=20
IMF (10$^3$ M$_\odot$)')...


In [1]:import matplotlib

In [2]:import pylab

In [3]:matplotlib.__version__
Out[3]:'0.87.7'

In [4]:matplotlib.__revision__
Out[4]:'$Revision: 2905 $'

In [5]:matplotlib.rc('text',usetex=3DTrue)

In [6]:pylab.plot([0,1])
Out[6]:[<matplotlib.lines.Line2D instance at 0xb67b7e4c>]

In [7]:pylab.xlabel(r'(10$^3$ M$_\odot$)')
Out[7]:<matplotlib.text.Text instance at 0xb691762c>

In [8]:pylab.savefig('toto1.eps')

In [9]:pylab.close()

In [10]:pylab.plot([1,2])
Out[10]:[<matplotlib.lines.Line2D instance at 0xb67d7fec>]

In [11]:pylab.xlabel(r'Upper mass for the IMF (10$^3$ M$_\odot$)')
Out[11]:<matplotlib.text.Text instance at 0xb67d0c6c>

In [12]:pylab.savefig('toto2.eps')

In [13]:pylab.close()

In [14]:pylab.plot([0,1])
Out[14]:[<matplotlib.lines.Line2D instance at 0xb67f078c>]

In [15]:pylab.xlabel(r'Upper mass for the IMF (10$^3$ M$_\odot$)')
Out[15]:<matplotlib.text.Text instance at 0xb63413ac>

In [16]:pylab.savefig('toto3.eps')
sh: line 1: 19756 Erreur de segmentation  gs -dBATCH -dNOPAUSE -r6000=20
-sDEVICE=3Dpswrite -sPAPERSIZE=3Dletter=20
-sOutputFile=3D"/tmp/11701f1f88db8c691a0ca6ac520c7706.ps"=20
"/tmp/11701f1f88db8c691a0ca6ac520c7706"=20
 >"/tmp/11701f1f88db8c691a0ca6ac520c7706.output"
-------------------------------------------------------------------------=
--
exceptions.RuntimeError                              Traceback (most=20
recent call last)

/home/champavert/<ipython console>

/usr/local/lib/python2.4/site-packages/matplotlib/pylab.py in=20
savefig(*args, **kwargs)
    811 def savefig(*args, **kwargs):
    812     fig =3D gcf()
--> 813     return fig.savefig(*args, **kwargs)
    814 if Figure.savefig.__doc__ is not None:
    815     savefig.__doc__ =3D _shift_string(Figure.savefig.__doc__)

/usr/local/lib/python2.4/site-packages/matplotlib/figure.py in=20
savefig(self, *args, **kwargs)
    685                 kwargs[key] =3D rcParams['savefig.%s'%key]
    686
--> 687         self.canvas.print_figure(*args, **kwargs)
    688
    689     def colorbar(self, mappable, cax=3DNone, **kw):

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_tkagg.=
py=20
in print_figure(self, filename, dpi, facecolor, edgecolor, orientation,=20
**kwargs)
    184         if dpi is None: dpi =3D rcParams['savefig.dpi']
    185         agg =3D self.switch_backends(FigureCanvasAgg)
--> 186         agg.print_figure(filename, dpi, facecolor, edgecolor,=20
orientation,
    187                          **kwargs)
    188         self.figure.set_canvas(self)

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_agg.py=
=20
in print_figure(self, filename, dpi, facecolor, edgecolor, orientation,=20
**kwargs)
    486                 ps =3D self.switch_backends(FigureCanvasPS)
    487                 ps.print_figure(filename, dpi, facecolor, edgecol=
or,
--> 488                                 orientation, **kwargs)
    489             elif ext.find('pdf')>=3D0:
    490                 from backend_pdf import FigureCanvasPdf

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_ps.py=20
in print_figure(self, outfile, dpi, facecolor, edgecolor, orientation,=20
papertype)
   1009             # Let's keep the usetex stuff seperate from the=20
generic postscript
   1010             self._print_figure_tex(outfile, dpi, facecolor,=20
edgecolor,
-> 1011                                    orientation, papertype)
   1012         else:
   1013             if  isinstance(outfile, file):

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_ps.py=20
in _print_figure_tex(self, outfile, dpi, facecolor, edgecolor,=20
orientation, papertype)
   1243         elif rcParams['text.usetex']:
   1244             if False: pass # for debugging
-> 1245             else: gs_distill(tmpfile, ext=3D=3D'.eps',=20
ptype=3Dpapertype, bbox=3Dbbox)
   1246
   1247         if  isinstance(outfile, file):

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_ps.py=20
in gs_distill(tmpfile, eps, ptype, bbox)
   1341     exit_status =3D os.system(command)
   1342     fh =3D file(outfile)
-> 1343     if exit_status: raise RuntimeError('ghostscript was not able=20
to process \
   1344 your image.\nHere is the full report generated by=20
ghostscript:\n\n' + fh.read())
   1345     else: verbose.report(fh.read(), 'debug')

RuntimeError: ghostscript was not able to process your image.
Here is the full report generated by ghostscript:

ESP Ghostscript 8.15 (2006-04-19)
Copyright (C) 2004 artofcode LLC, Benicia, CA.  All rights reserved.
This software comes with NO WARRANTY: see the file COPYING for details.

Nicolas Champavert wrote:
> Hello,
> 
>   I have some problems when trying to save a figure with usetex=True. 
> Sometimes, it is not possible to save the figure when trying to put an 
> xlabel with LaTeX inside.
> It works with pylab.xlabel('M$_\odot$') but not with 
> pylab.xlabel('10$^3$ M$_\odot$') (see below). Do you know why ?
> 


Works fine here, with and w/o raw strings.

In [75]: rcParams['text.usetex']=True

In [76]: plot([1,2,3])
Out[76]: [<matplotlib.lines.Line2D instance at 0xa0db754c>]

In [77]: xlabel('10$^3$ M$_\odot$')
Out[77]: <matplotlib.text.Text instance at 0xa0daea2c>

In [78]: savefig('test.eps')

In [79]: matplotlib.__version__
Out[79]: '0.87.7'

In [80]: matplotlib.__revision__
Out[80]: '$Revision: 2835 $'


Maybe you need to upgrade, but that's just a guess.

-- 
cheers,
steve

Random number generation is the art of producing pure gibberish as
quickly as possible.

I haven't tried it, but my guess is the '\' character is the problem.

> pylab.xlabel('10$^3$ M$_\odot$')

Try
pylab.xlabel(r'10$^3$ M$_\odot$')
              ^
              Add raw string marker.

or maybe
pylab.xlabel('10$^3$ M$_\\odot$')

Gary R.

Nicolas Champavert wrote:
> Hello,
> 
>   I have some problems when trying to save a figure with usetex=True. 
> Sometimes, it is not possible to save the figure when trying to put an 
> xlabel with LaTeX inside.
> It works with pylab.xlabel('M$_\odot$') but not with 
> pylab.xlabel('10$^3$ M$_\odot$') (see below). Do you know why ?

On Monday 11 December 2006 7:12 am, Nicolas Champavert wrote:
> Hello,
>
>   I have some problems when trying to save a figure with usetex=True.
> Sometimes, it is not possible to save the figure when trying to put an
> xlabel with LaTeX inside.
> It works with pylab.xlabel('M$_\odot$') but not with
> pylab.xlabel('10$^3$ M$_\odot$') (see below). Do you know why ?

You're example works on my system. But note, you should use raw strings, maybe 
that is the source of your problem:

pylab.xlabel(r'10$^3$ M$_\odot$')

Hello,

  I have some problems when trying to save a figure with usetex=True. 
Sometimes, it is not possible to save the figure when trying to put an 
xlabel with LaTeX inside.
It works with pylab.xlabel('M$_\odot$') but not with 
pylab.xlabel('10$^3$ M$_\odot$') (see below). Do you know why ?

In [1]:import matplotlib

In [2]:matplotlib.__version__
Out[2]:'0.87.7'

In [3]:import pylab

In [4]:a=[0,1]

In [5]:pylab.plot(a)
Out[5]:[<matplotlib.lines.Line2D instance at 0xb690472c>]

In [6]:pylab.xlabel('M$_\odot$')
Out[6]:<matplotlib.text.Text instance at 0xb6976d2c>

In [7]:pylab.savefig('toto.eps')

In [8]:matplotlib.rc('text',usetex=True)

In [9]:pylab.plot(a)
Out[9]:[<matplotlib.lines.Line2D instance at 0xb692466c>]

In [10]:pylab.xlabel('M$_\odot$')
Out[10]:<matplotlib.text.Text instance at 0xb6916e2c>

In [11]:pylab.savefig('toto.eps')

In [12]:matplotlib.rc('text',usetex=False)

In [13]:pylab.plot(a)
Out[13]:[<matplotlib.lines.Line2D instance at 0xb655cb8c>]

In [14]:pylab.xlabel('10$^3$ M$_\odot$')
Out[14]:<matplotlib.text.Text instance at 0xb65586ac>

In [15]:pylab.savefig('toto.eps')

In [16]:matplotlib.rc('text',usetex=True)

In [17]:pylab.plot(a)
Out[17]:[<matplotlib.lines.Line2D instance at 0xb657286c>]

In [18]:pylab.xlabel('10$^3$ M$_\odot$')
Out[18]:<matplotlib.text.Text instance at 0xb656af6c>

In [19]:pylab.savefig('toto.eps')
sh: line 1: 16796 Erreur de segmentation  gs -dBATCH -dNOPAUSE -r6000 
-sDEVICE=pswrite -sPAPERSIZE=letter 
-sOutputFile="/tmp/f71dbe52628a3f83a77ab494817525c6.ps" 
"/tmp/f71dbe52628a3f83a77ab494817525c6" 
 >"/tmp/f71dbe52628a3f83a77ab494817525c6.output"
---------------------------------------------------------------------------
exceptions.RuntimeError                              Traceback (most 
recent call last)

/home/champavert/<ipython console>

/usr/local/lib/python2.4/site-packages/matplotlib/pylab.py in 
savefig(*args, **kwargs)
    812 def savefig(*args, **kwargs):
    813     fig = gcf()
--> 814     return fig.savefig(*args, **kwargs)
    815 if Figure.savefig.__doc__ is not None:
    816     savefig.__doc__ = _shift_string(Figure.savefig.__doc__)

/usr/local/lib/python2.4/site-packages/matplotlib/figure.py in 
savefig(self, *args, **kwargs)
    685                 kwargs[key] = rcParams['savefig.%s'%key]
    686
--> 687         self.canvas.print_figure(*args, **kwargs)
    688
    689     def colorbar(self, mappable, cax=None, **kw):

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_tkagg.py 
in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, 
**kwargs)
    184         if dpi is None: dpi = rcParams['savefig.dpi']
    185         agg = self.switch_backends(FigureCanvasAgg)
--> 186         agg.print_figure(filename, dpi, facecolor, edgecolor, 
orientation,
    187                          **kwargs)
    188         self.figure.set_canvas(self)

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_agg.py 
in print_figure(self, filename, dpi, facecolor, edgecolor, orientation, 
**kwargs)
    486                 ps = self.switch_backends(FigureCanvasPS)
    487                 ps.print_figure(filename, dpi, facecolor, edgecolor,
--> 488                                 orientation, **kwargs)
    489             elif ext.find('pdf')>=0:
    490                 from backend_pdf import FigureCanvasPdf

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_ps.py 
in print_figure(self, outfile, dpi, facecolor, edgecolor, orientation, 
papertype)
   1009             # Let's keep the usetex stuff seperate from the 
generic postscript
   1010             self._print_figure_tex(outfile, dpi, facecolor, 
edgecolor,
-> 1011                                    orientation, papertype)
   1012         else:
   1013             if  isinstance(outfile, file):

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_ps.py 
in _print_figure_tex(self, outfile, dpi, facecolor, edgecolor, 
orientation, papertype)
   1243         elif rcParams['text.usetex']:
   1244             if False: pass # for debugging
-> 1245             else: gs_distill(tmpfile, ext=='.eps', 
ptype=papertype, bbox=bbox)
   1246
   1247         if  isinstance(outfile, file):

/usr/local/lib/python2.4/site-packages/matplotlib/backends/backend_ps.py 
in gs_distill(tmpfile, eps, ptype, bbox)
   1341     exit_status = os.system(command)
   1342     fh = file(outfile)
-> 1343     if exit_status: raise RuntimeError('ghostscript was not able 
to process \
   1344 your image.\nHere is the full report generated by 
ghostscript:\n\n' + fh.read())
   1345     else: verbose.report(fh.read(), 'debug')

RuntimeError: ghostscript was not able to process your image.
Here is the full report generated by ghostscript:

ESP Ghostscript 8.15 (2006-04-19)
Copyright (C) 2004 artofcode LLC, Benicia, CA.  All rights reserved.
This software comes with NO WARRANTY: see the file COPYING for details.


Nicolas

Eric Firing wrote:
> Robert Cimrman wrote:
>> Eric Firing wrote:
>>> Robert and any other spy users:
>>>
>>> I have committed to svn a new axes method, spy3, that combines a 
>>> modification of the functionality of both spy and spy2.  I hope you 
>>> can check it out.  If it looks OK, then I would like to simply 
>>> replace spy and spy2 with this combined version.  In that case the 
>>> pylab interface, which now gives access to spy and spy2, would have a 
>>> single spy function which would access the new version.  My suspicion 
>>> is that spy is used almost entirely in interactive mode, and probably 
>>> not by very many people, so that this changeover can be made quickly 
>>> with little disruption to present users.
>>>
>>> Attached is a script illustrating the difference in the way spy3 
>>> displays a matrix (it matches the way it is printed: first index is 
>>> row number, second is column number, row number increases down) 
>>> versus what spy and spy2 do (first index is X, second index is Y).
>>>
>>> Also attached is the diff for spy3.
>>>
>>> Users may want to comment in particular on the default for the 
>>> "aspect" kwarg.  Presently it is set to "equal" so that the shape of 
>>> the plot is the shape of the array with square cells.  This differs 
>>> from spy and spy2.  The rationale is that it gives the best picture 
>>> of what the array looks like, including its shape.
>>
>> Thumbs up :), just add the sparse-full matrix switch to the imshow 
>> branch too, if possible. But I am happy with it as it is.
 >
> The sparse-full difference only works with the plot mode; for an image 
> there is no alternative to providing a value for every pixel, so I don't 
> know of any way to optimize it for the case of sparse storage.  A 
> polygon collection could be used to achieve the same result in this 
> case.  I'm not sure it is a good idea, though, because there would be an 
> advantage of not converting to a regular array only in the case where 
> the array is so large that such a conversion would use a big chunk of 
> memory, and in that case the polygons probably would be less than 
> single-pixel size anyway, so one would be better off using the present 
> symbol-plotting mode.

Yeah, I have tried to write it myself before I posted this message but 
found that it probably would not work well - nevertheless I asked :).
What could be done, though, is to raise an exception explaining that 
sparse matrices and the image mode don't like each other; as it is, the 
function spy3 just dies on asarray (should be st. like asarray( 
Z.todense() ))

In [1]:import numpy as nm
In [2]:import scipy.sparse as sp
In [3]:a = nm.array( [[0, 1], [0,1], [2,3]] )
In [4]:b = sp.csr_matrix( a )
In [5]:gca().spy3( b )
---------------------------------------------------------------------------
exceptions.TypeError                                 Traceback (most 
recent call last)

/home/eldaran/<console>

/usr/lib/python2.4/site-packages/matplotlib/axes.py in spy3(self, Z, 
precision, marker, markersize, aspect, **kwargs)
    4377         """
    4378         if marker is None and markersize is None:
-> 4379             Z = asarray(Z)
    4380             if precision is None: mask = Z!=0.
    4381             else:                 mask = absolute(Z)>precision

/usr/lib/python2.4/site-packages/numarray/numarraycore.py in 
asarray(seq, type, typecode, dtype)
     432     if isinstance(seq, _gen.NDArray) and type is None and 
typecode is None:
     433         return seq
--> 434     return array(seq, type=type, typecode=typecode, copy=0, 
dtype=dtype)
     435
     436 inputarray = asarray   # Obsolete synonym

/usr/lib/python2.4/site-packages/numarray/numarraycore.py in 
array(sequence, typecode, copy, savespace, type, shape, dtype)
     415     if (hasattr(sequence,'__getitem__')
     416         and hasattr(sequence,'__len__')):
--> 417         return fromlist(sequence,type,shape)
     418
     419     ##SEQUENCE is a scalar or unhandleable

/usr/lib/python2.4/site-packages/numarray/numarraycore.py in 
fromlist(seq, type, shape, check_overflow, typecode, dtype)
     246         return arr
     247
--> 248     if not len(seq) and type is None:
     249         type = _nt.Long
     250

/home/share/software/usr/lib/python2.4/site-packages/scipy/sparse/sparse.py 
in __len__(self)
     163     def __len__(self):
     164         # return self.getnnz()
--> 165         raise TypeError, "sparse matrix length is ambiguous; use 
getnnz()" \
     166                          " or shape[0]"
     167



> Anyway, I'm glad it works for you.  Thanks for checking.

Thanks for your fast help!
r.

On Sunday 10 December 2006 21:14, Chuang wrote:
> Hi there,
>
> I wanna plot two curves, and save to 2 different files. However, when I
> used the following code, the 2nd file contains both the 2 curves.
>
> plot(X1,Y1)
> savefig('file1.png')
> plot(X2,Y2)
> savefig('file2.png')
>
> It seems like the program memorize both of the two curves and save to
> the 2nd file. How can I save only the 2nd curve in the 2nd file?

Possibility #1: Create a new figure before the second plot
>>>plot(x1,y1)
>>>figure()
>>>plot(x2,y2)

Possibility #2: Clear the figure before the second plot 
>>>plot(x1,y1)
>>>clf()
>>>plot(x2,y2)

Possibility #3: Force the current axes to refresh, by setting its "hold" 
property to "False"
>>>plot(x1,y1)
>>>gca().hold(False)
>>>plot(x2,y2)

Possibiltiy #4: Get familiar with the more pythonesque functions.

Hi there,

I wanna plot two curves, and save to 2 different files. However, when I
used the following code, the 2nd file contains both the 2 curves.

plot(X1,Y1)
savefig('file1.png')
plot(X2,Y2)
savefig('file2.png')

It seems like the program memorize both of the two curves and save to
the 2nd file. How can I save only the 2nd curve in the 2nd file? 

Thanks,
CC