# RuntimeError: Could not open facefile

Hi,
I’m running into this RuntimeError: Could not open facefile c:\Python32\lib\site-packages\matplotlib\mpl-data\fonts\ttf\Vera.ttf; Cannot_Open_Resource when I’m trying to save out a series of *.png files in a loop. It crashes on this error after many passes through the loop and successful files get created, but then always on the same pass it does this. The full traceback is here:

File “C:\Users\E440710\Desktop\PythonTransfer\fittslaw_ThroughputCalc_AS_break.py”, line 744, in
fig.savefig(fname, transparent = True)
File “c:\Python32\lib\site-packages\matplotlib\figure.py”, line 1174, in savefig
self.canvas.print_figure(*args, **kwargs)
File “c:\Python32\lib\site-packages\matplotlib\backend_bases.py”, line 2027, in print_figure
**kwargs)
File “c:\Python32\lib\site-packages\matplotlib\backends\backend_agg.py”, line 451, in print_png
FigureCanvasAgg.draw(self)
File “c:\Python32\lib\site-packages\matplotlib\backends\backend_agg.py”, line 400, in draw
self.figure.draw(self.renderer)
File “c:\Python32\lib\site-packages\matplotlib\artist.py”, line 56, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File “c:\Python32\lib\site-packages\matplotlib\figure.py”, line 887, in draw
func(*args)
File “c:\Python32\lib\site-packages\matplotlib\artist.py”, line 56, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File “c:\Python32\lib\site-packages\matplotlib\axes.py”, line 1985, in draw
a.draw(renderer)
File “c:\Python32\lib\site-packages\matplotlib\artist.py”, line 56, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File “c:\Python32\lib\site-packages\matplotlib\axis.py”, line 1043, in draw
ticklabelBoxes, ticklabelBoxes2 = self._get_tick_bboxes(ticks_to_draw, renderer)
File “c:\Python32\lib\site-packages\matplotlib\axis.py”, line 994, in _get_tick_bboxes
extent = tick.label1.get_window_extent(renderer)
File “c:\Python32\lib\site-packages\matplotlib\text.py”, line 743, in get_window_extent
bbox, info = self._get_layout(self._renderer)
File “c:\Python32\lib\site-packages\matplotlib\text.py”, line 296, in _get_layout
ismath=False)
File “c:\Python32\lib\site-packages\matplotlib\backends\backend_agg.py”, line 182, in get_text_width_height_descent
font = self._get_agg_font(prop)
File “c:\Python32\lib\site-packages\matplotlib\backends\backend_agg.py”, line 223, in _get_agg_font
font = FT2Font(str(fname))
RuntimeError: Could not open facefile c:\Python32\lib\site-packages\matplotlib\mpl-data\fonts\ttf\Vera.ttf; Cannot_Open_Resource

I’ve tried the various fixes that have been suggested - removing the fontList.py3k.cache and even the removing the .matplotlib directory. However when I run my script that’s producing the error the directory gets recreated along with the fontList.py3k.cache which must be pointing to the wrong path?

When I check the path c:\Python32\lib\site-packages\matplotlib\mpl-data\fonts\ttf\Vera.ttf where matplotlib is looking for the resource it cannot open - the Vera.ttf is there.

This only happens after many iterations through the loop that is saving out the *.png files and I have no idea why.

The relevant code from my script is here:

for p in plotData[k][“data”]:
#print(“p in plotData[k]:”,p)
a = numpy.array((loc[0],loc[1]))
b = numpy.array((p[0],p[1]))
distValue = (numpy.sqrt(numpy.sum((a-b)**2) ))/86.0 #divide by 86 because that was the ppi on the display used to collect the data
if p[2] == 1:
hit_x.append(loc[0]-p[0])

            hit_y.append(loc[1]-p[1])

frame_hit_x = loc[0]-p[0]
frame_hit_y = loc[1]-p[1]
print("frame_x:", frame_hit_x)
files = []
if size == (0.25,0.25) and makeMovie:

fig = plt.figure()
print("fig:", fig)
plt.plot(frame_hit_x,frame_hit_y,color='green',marker='o',linestyle='')

plt.axis('scaled')
plt.axis([-100,100,-100,100])

fname = "subj{:g}_size{:g}_hit_x{:g}.png".format(Subject,btnSize,frame_hit_x)
print('saving frame', fname)
fig.savefig(fname, transparent = True)
files.append(fname)


I’m on a Win7 64bit using python 3.2 and matplotlib version 1.2.x

Any help would be greatly appreciated!

Andy

This is a known bug on Windows where it runs out of file handles
after a while.

This commit was an attempt to fix it, but it doesn't seem to work:


https://github.com/matplotlib/matplotlib/commit/4cb2aaa87b0aa9efe7178d7510d3d091ef5206df

I think we need a Windows user/developer/expert to get to the bottom


of why file handles are not being freed to the OS.

Mike

···

Ok thank you - so one way to work around it is to just generate the files I want in batches so Windows won’t run out of file handles - but is there a way to know how many handles are available? I’m trying to animate some data and I don’t really know how many frames there are - could be thousands.

Andy

···

On Fri, Mar 23, 2012 at 3:45 PM, Michael Droettboom <mdroe@…86…> wrote:

This is a known bug on Windows where it runs out of file handles


after a while.

This commit was an attempt to fix it, but it doesn't seem to work:

[https://github.com/matplotlib/matplotlib/commit/4cb2aaa87b0aa9efe7178d7510d3d091ef5206df](https://github.com/matplotlib/matplotlib/commit/4cb2aaa87b0aa9efe7178d7510d3d091ef5206df)

I think we need a Windows user/developer/expert to get to the bottom


of why file handles are not being freed to the OS.

Mike

On 03/23/2012 04:35 PM, Andrew Smart wrote:


Hi,

  I'm running into this RuntimeError: Could not open facefile


c:\Python32\lib\site-packages\matplotlib\mpl-data\fonts\ttf\Vera.ttf;
Cannot_Open_Resource when I’m trying to save out a series of *.png
files in a loop. It crashes on this error after many passes
through the loop and successful files get created, but then always
on the same pass it does this. The full traceback is here:

    File


“C:\Users\E440710\Desktop\PythonTransfer\fittslaw_ThroughputCalc_AS_break.py”,
line 744, in

      fig.savefig(fname, transparent = True)

File "c:\Python32\lib\site-packages\matplotlib\figure.py", line


1174, in savefig

      self.canvas.print_figure(*args, **kwargs)

File


“c:\Python32\lib\site-packages\matplotlib\backend_bases.py”, line
2027, in print_figure

      **kwargs)

File


“c:\Python32\lib\site-packages\matplotlib\backends\backend_agg.py”,
line 451, in print_png

      FigureCanvasAgg.draw(self)

File


“c:\Python32\lib\site-packages\matplotlib\backends\backend_agg.py”,
line 400, in draw

      self.figure.draw(self.renderer)

File "c:\Python32\lib\site-packages\matplotlib\artist.py", line


56, in draw_wrapper

      draw(artist, renderer, *args, **kwargs)

File "c:\Python32\lib\site-packages\matplotlib\figure.py", line


887, in draw

      func(*args)

File "c:\Python32\lib\site-packages\matplotlib\artist.py", line


56, in draw_wrapper

      draw(artist, renderer, *args, **kwargs)

File "c:\Python32\lib\site-packages\matplotlib\axes.py", line


1985, in draw

      a.draw(renderer)

File "c:\Python32\lib\site-packages\matplotlib\artist.py", line


56, in draw_wrapper

      draw(artist, renderer, *args, **kwargs)

File "c:\Python32\lib\site-packages\matplotlib\axis.py", line


1043, in draw

      ticklabelBoxes, ticklabelBoxes2 =


self._get_tick_bboxes(ticks_to_draw, renderer)

    File "c:\Python32\lib\site-packages\matplotlib\axis.py", line


994, in _get_tick_bboxes

      extent = tick.label1.get_window_extent(renderer)

File "c:\Python32\lib\site-packages\matplotlib\text.py", line


743, in get_window_extent

      bbox, info = self._get_layout(self._renderer)

File "c:\Python32\lib\site-packages\matplotlib\text.py", line


296, in _get_layout

      ismath=False)

File


“c:\Python32\lib\site-packages\matplotlib\backends\backend_agg.py”,
line 182, in get_text_width_height_descent

      font = self._get_agg_font(prop)

File


“c:\Python32\lib\site-packages\matplotlib\backends\backend_agg.py”,
line 223, in _get_agg_font

      font = FT2Font(str(fname))

RuntimeError: Could not open facefile


c:\Python32\lib\site-packages\matplotlib\mpl-data\fonts\ttf\Vera.ttf;
Cannot_Open_Resource

  I've tried the various fixes that have been suggested - removing


the fontList.py3k.cache and even the removing the .matplotlib
directory. However when I run my script that’s producing the error
the directory gets recreated along with the fontList.py3k.cache
which must be pointing to the wrong path?

  When I check the path


c:\Python32\lib\site-packages\matplotlib\mpl-data\fonts\ttf\Vera.ttf
where matplotlib is looking for the resource it cannot open - the
Vera.ttf is there.

  This only happens after many iterations through the loop that is


saving out the *.png files and I have no idea why.

  The relevant code from my script is here:

for p in plotData[k]["data"]:

#print("p in plotData[k]:",p)

a = numpy.array((loc[0],loc[1]))

b = numpy.array((p[0],p[1]))

distValue = (numpy.sqrt(numpy.sum((a-b)**2) ))/86.0


#divide by 86 because that was the ppi on the display used to
collect the data

              if p[2] == 1:

hit_x.append(loc[0]-p[0])

hit_y.append(loc[1]-p[1])

frame_hit_x = loc[0]-p[0]

frame_hit_y = loc[1]-p[1]

print("frame_x:", frame_hit_x)

files = []

if size == (0.25,0.25) and makeMovie:

fig = plt.figure()

print("fig:", fig)


plt.plot(frame_hit_x,frame_hit_y,color=‘green’,marker=‘o’,linestyle=’’)

                      plt.axis('scaled')

plt.axis([-100,100,-100,100])

fname =


“subj{:g}_size{:g}_hit_x{:g}.png”.format(Subject,btnSize,frame_hit_x)

                      print('saving frame', fname)

fig.savefig(fname, transparent = True)

files.append(fname)

I'm on a Win7 64bit using python 3.2 and matplotlib version 1.2.x

Any help would be greatly appreciated!

Andy

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I wonder if the solution is as simple as doing font caching at the class level rather than instance level. Andrew, could you try editing matplotlib/backends/backend_agg.py and replace

class RendererAgg(RendererBase):

“”"

The renderer handles all the drawing primitives using a graphics

context instance that controls the colors/styles

“”"

debug=1

def init(self, width, height, dpi):

if debug: verbose.report(‘RendererAgg.init’, ‘debug-annoying’)

RendererBase.init(self)

self.texd = maxdict(50) # a cache of tex image rasters

self._fontd = maxdict(50)

with

class RendererAgg(RendererBase):

“”"

The renderer handles all the drawing primitives using a graphics

context instance that controls the colors/styles

“”"

debug=1

_fontd = maxdict(50)

texd = maxdict(50) # a cache of tex image rasters

def init(self, width, height, dpi):

if debug: verbose.report(‘RendererAgg.init’, ‘debug-annoying’)

RendererBase.init(self)

Does anyone see an issue with doing this caching at the class level? If this works, we should have many fewer font files parsed.

w/o modifying the src code, a related way to test this idea is to reuse the same figure instance and clear it at the start of the loop. Ie, rather than

for i in range(N):

fig = plt.figure()

…plot_something

fig.savefig(…)

do

fig = plt.figure()

for i in range(N):

fig.clf()

…plot_something

fig.savefig(…)

I would try the latter first, and if that works I would appreciate it if you test the src code modification unless someone chimes in and tells us that is a really bad idea.

JDH

···

On Fri, Mar 23, 2012 at 3:35 PM, Andrew Smart <andrew.johnsmart@…287…> wrote:

Hi,
I’m running into this RuntimeError: Could not open facefile c:\Python32\lib\site-packages\matplotlib\mpl-data\fonts\ttf\Vera.ttf; Cannot_Open_Resource when I’m trying to save out a series of *.png files in a loop. It crashes on this error after many passes through the loop and successful files get created, but then always on the same pass it does this. The full traceback is here: