matplotlib-devel

[matplotlib-devel] error with basemap and pdf

[Michael H. <mh...@us...>]

I have attached a PDF created with matplotib/basemap.  On my mac,  
Preview opens this file without any errors.  However, Adobe Acrobat  
9.2.0 (Mac) reports this error:

"An error exists on this page. Acrobat may not display the page  
correctly. Please contact the person who created the PDF document to  
correct the problem."

It then goes ahead and displays the image correctly.

I have found similar issues with Illustrator, and older versions of  
Acrobat Professional where those pieces of software are unable to open  
the PDF at all.

The only free software I could find to validate PDFs (http://multivalent.sourceforge.net/index.html 
) has no complaints about this file.

Does anyone have any idea what might be causing these errors to  
(sometimes) occur?

Info:
matplotlib: 0.99.0
basemap: 0.99.4

The code that created the PDF is below:
#!/usr/bin/env python

import matplotlib
matplotlib.use('agg')
from mpl_toolkits.basemap import Basemap
from pylab import savefig,close,figure,arange,array

figwidth=6
figheight=6
clat = 39.132332
clon = -98.261719
fig = figure(figsize=(figwidth,figheight),edgecolor='g',facecolor='g')
ax1 = fig.add_axes([0,0,1.0,1.0])

map = Basemap(resolution='c',
               projection='ortho',
               lon_0=clon,lat_0=clat,ax=ax1)

map.drawcountries(linewidth=0.1,color=[0.2,0.2,0.2])
map.drawcoastlines(linewidth=0.05,color=[0.2,0.2,0.2])
map.drawlsmask((230,230,230,255),(119,155,207,255))
meridians = arange(-180,210,30)
parallels = arange(-90,120,30)
map 
.drawmeridians(meridians,linewidth=0.1,dashes=[1,0],color=[0.2,0.2,0.2])
map 
.drawparallels(parallels,linewidth=0.1,dashes=[1,0],color=[0.2,0.2,0.2])
pcx,pcy = map(clon,clat)
map 
.plot 
(array 
([pcx]),array([pcy]),'ro',linewidth=1,markersize=5,markeredgecolor='r')
map.drawmapboundary(color='k',linewidth=2.0)

savefig('testfig.pdf')


close('all')

Re: [matplotlib-devel] error with basemap and pdf

[Jouni K. S. <jk...@ik...>]

Michael Hearne <mh...@us...> writes:

> I have attached a PDF created with matplotib/basemap.  On my mac,
> Preview opens this file without any errors.  However, Adobe Acrobat
> 9.2.0 (Mac) reports this error:
>
> "An error exists on this page. Acrobat may not display the page
> correctly. Please contact the person who created the PDF document to
> correct the problem."

This is probably a bug in the pdf backend. Ghostscript 8.62 complains
with "Error: /nocurrentpoint in --run--". This suggests that an "m"
(moveto) command is missing somewhere. I'm too busy to debug this today,
but please file a bug in the tracker.

-- 
Jouni K. Seppänen
http://www.iki.fi/jks

Re: [matplotlib-devel] error with basemap and pdf

[Jouni K. S. <jk...@ik...>]

Could somebody test that script with current trunk (rev. 7899)? I don't
have basemap installed, but I think my latest change might shake out the
bug.

-- 
Jouni K. Seppänen
http://www.iki.fi/jks

Re: [matplotlib-devel] error with basemap and pdf

[Jeff W. <js...@fa...>]

Jouni K. Seppänen wrote:
> Could somebody test that script with current trunk (rev. 7899)? I don't
> have basemap installed, but I think my latest change might shake out the
> bug.
>
>   
Jouni:  That test script now crashes with:

Traceback (most recent call last):
  File "testpdf.py", line 28, in <module>
    savefig('testfig.pdf')
  File "/Users/jwhitaker/lib/python/matplotlib/pyplot.py", line 355, in 
savefig
    return fig.savefig(*args, **kwargs)
  File "/Users/jwhitaker/lib/python/matplotlib/figure.py", line 1055, in 
savefig
    self.canvas.print_figure(*args, **kwargs)
  File "/Users/jwhitaker/lib/python/matplotlib/backend_bases.py", line 
1618, in print_figure
    **kwargs)
  File "/Users/jwhitaker/lib/python/matplotlib/backend_bases.py", line 
1476, in print_pdf
    return pdf.print_pdf(*args, **kwargs)
  File "/Users/jwhitaker/lib/python/matplotlib/backends/backend_pdf.py", 
line 2094, in print_pdf
    self.figure.draw(renderer)
  File "/Users/jwhitaker/lib/python/matplotlib/artist.py", line 55, in 
draw_wrapper
    draw(artist, renderer, *kl)
  File "/Users/jwhitaker/lib/python/matplotlib/figure.py", line 772, in draw
    for a in self.axes: a.draw(renderer)
  File "/Users/jwhitaker/lib/python/matplotlib/artist.py", line 55, in 
draw_wrapper
    draw(artist, renderer, *kl)
  File "/Users/jwhitaker/lib/python/matplotlib/axes.py", line 1761, in draw
    a.draw(renderer)
  File "/Users/jwhitaker/lib/python/matplotlib/artist.py", line 55, in 
draw_wrapper
    draw(artist, renderer, *kl)
  File "/Users/jwhitaker/lib/python/matplotlib/lines.py", line 533, in draw
    drawFunc(renderer, gc, tpath, affine.frozen())
  File "/Users/jwhitaker/lib/python/matplotlib/lines.py", line 869, in 
_draw_lines
    self._lineFunc(renderer, gc, path, trans)
  File "/Users/jwhitaker/lib/python/matplotlib/lines.py", line 920, in 
_draw_dashed
    renderer.draw_path(gc, path, trans)
  File "/Users/jwhitaker/lib/python/matplotlib/backends/backend_pdf.py", 
line 1353, in draw_path
    rgbFace is None and gc.get_hatch_path() is None)
  File "/Users/jwhitaker/lib/python/matplotlib/backends/backend_pdf.py", 
line 1235, in writePath
    cmds = self.pathOperations(path, transform, clip)
  File "/Users/jwhitaker/lib/python/matplotlib/backends/backend_pdf.py", 
line 1214, in pathOperations
    raise ValueError, 'Path lacks initial MOVETO'
ValueError: Path lacks initial MOVETO

-- 
Jeffrey S. Whitaker         Phone  : (303)497-6313
Meteorologist               FAX    : (303)497-6449
NOAA/OAR/PSD  R/PSD1        Email  : Jef...@no...
325 Broadway                Office : Skaggs Research Cntr 1D-113
Boulder, CO, USA 80303-3328 Web    : http://tinyurl.com/5telg

Re: [matplotlib-devel] Should Path objects have an initial MOVETO? (was: error with basemap and pdf)

[Michael D. <md...@st...>]

Jouni K. Seppänen wrote:
> Jeff Whitaker <js...@fa...> writes:
>
>   
>> Jouni:  That test script now crashes with:
>>
>>   File "/Users/jwhitaker/lib/python/matplotlib/backends/backend_pdf.py", 
>> line 1214, in pathOperations
>>     raise ValueError, 'Path lacks initial MOVETO'
>> ValueError: Path lacks initial MOVETO
>>     
>
> I think this confirms my suspicion that the bug is really elsewhere. A
> path in PDF needs to begin with a "m" that sets the initial point, and
> that particular Path object only consisted of one LINETO operation. Am I
> correct in thinking that this is an invalid path?
>   
Yes -- that path should be considered invalid, though the Path class 
doesn't do any verification.  I'll add this.  I'm surprised that it's 
coming from the line class, which in general doesn't allow for 
customization of the path codes.  There must be something unanticipated 
happening.

Cheers,
Mike

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

Re: [matplotlib-devel] Should Path objects have an initial MOVETO?

[Michael D. <md...@st...>]

The bug was actually in the path simplification.  In really degenerate 
cases (bravo for finding it) of paths that are completely outside of the 
clip region, it would create a path with a single LINETO command.

This is now fixed in SVN on the branch and trunk.

Mike

Michael Droettboom wrote:
> Jouni K. Seppänen wrote:
>   
>> Jeff Whitaker <js...@fa...> writes:
>>
>>   
>>     
>>> Jouni:  That test script now crashes with:
>>>
>>>   File "/Users/jwhitaker/lib/python/matplotlib/backends/backend_pdf.py", 
>>> line 1214, in pathOperations
>>>     raise ValueError, 'Path lacks initial MOVETO'
>>> ValueError: Path lacks initial MOVETO
>>>     
>>>       
>> I think this confirms my suspicion that the bug is really elsewhere. A
>> path in PDF needs to begin with a "m" that sets the initial point, and
>> that particular Path object only consisted of one LINETO operation. Am I
>> correct in thinking that this is an invalid path?
>>   
>>     
> Yes -- that path should be considered invalid, though the Path class 
> doesn't do any verification.  I'll add this.  I'm surprised that it's 
> coming from the line class, which in general doesn't allow for 
> customization of the path codes.  There must be something unanticipated 
> happening.
>
> Cheers,
> Mike
>
>   

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

[matplotlib-devel] Should Path objects have an initial MOVETO? (was: error with basemap and pdf)

[Jouni K. S. <jk...@ik...>]

Jeff Whitaker <js...@fa...> writes:

> Jouni:  That test script now crashes with:
>
>   File "/Users/jwhitaker/lib/python/matplotlib/backends/backend_pdf.py", 
> line 1214, in pathOperations
>     raise ValueError, 'Path lacks initial MOVETO'
> ValueError: Path lacks initial MOVETO

I think this confirms my suspicion that the bug is really elsewhere. A
path in PDF needs to begin with a "m" that sets the initial point, and
that particular Path object only consisted of one LINETO operation. Am I
correct in thinking that this is an invalid path?

I'm not too familiar with Path (and I'm terribly busy today) but I think
the way to catch this bug is to add a sanity check to Path, similar to
the check in the pdf backend that produces that error. Then the
traceback would show what code is creating the invalid path -- the
traceback from the backend is too late in the execution to tell us that.

-- 
Jouni K. Seppänen
http://www.iki.fi/jks