Traceback (most recent call last):

 "<ipython-input-5-9e9c57cf4342>", line 1, in <module>
limit(lamda**k * exp(-lamda) / factorial(k), k, oo)

 "sympy/series/limits.py", line 42, in limit
return Limit(e, z, z0, dir).doit(deep=False)

 "sympy/series/limits.py", line 157, in doit
r = gruntz(e, z, z0, dir)

 "sympy/series/gruntz.py", line 637, in gruntz
r = limitinf(e, z)

 "sympy/core/cache.py", line 91, in wrapper
retval = cfunc(*args, **kwargs)

 "sympy/core/compatibility.py", line 872, in wrapper
result = user_function(*args, **kwds)

 "sympy/series/gruntz.py", line 420, in limitinf
c0, e0 = mrv_leadterm(e, x)

 "sympy/core/cache.py", line 91, in wrapper
retval = cfunc(*args, **kwargs)

 "sympy/core/compatibility.py", line 872, in wrapper
result = user_function(*args, **kwds)

 "sympy/series/gruntz.py", line 501, in mrv_leadterm
f, logw = rewrite(exps, Omega, x, w)

 "sympy/series/gruntz.py", line 573, in rewrite
raise NotImplementedError('Result depends on the sign of %s' % sig)NotImplementedError: Result depends on the sign of sign(log(lamda))
Traceback (most recent call last):


 "lib/matplotlib/sphinxext/plot_directive.py", line 612, in render_figures

figman.canvas.figure.savefig(img.filename(fmt), dpi=dpi)


 "lib/matplotlib/figure.py", line 2203, in savefig

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


 "lib/matplotlib/backend_bases.py", line 2105, in print_figure

**kwargs)


 "lib/matplotlib/backends/backend_pdf.py", line 2548, in print_pdf

self.figure.draw(renderer)


 "lib/matplotlib/artist.py", line 38, in draw_wrapper

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


 "lib/matplotlib/figure.py", line 1736, in draw

renderer, self, artists, self.suppressComposite)


 "lib/matplotlib/image.py", line 137, in _draw_list_compositing_images

a.draw(renderer)


 "lib/matplotlib/artist.py", line 38, in draw_wrapper

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


 "lib/matplotlib/axes/_base.py", line 2630, in draw

mimage._draw_list_compositing_images(renderer, self, artists)


 "lib/matplotlib/image.py", line 137, in _draw_list_compositing_images

a.draw(renderer)


 "lib/matplotlib/artist.py", line 38, in draw_wrapper

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


 "lib/matplotlib/axis.py", line 1229, in draw

renderer)


 "lib/matplotlib/axis.py", line 1174, in _get_tick_bboxes

for tick in ticks if tick.label1.get_visible()],


 "lib/matplotlib/axis.py", line 1174, in <listcomp>

for tick in ticks if tick.label1.get_visible()],


 "lib/matplotlib/text.py", line 905, in get_window_extent

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


 "lib/matplotlib/text.py", line 293, in _get_layout

ismath="TeX" if self.get_usetex() else False)


 "lib/matplotlib/backends/_backend_pdf_ps.py", line 62, in get_text_width_height_descent

font.set_text(s, 0.0, flags=ft2font.LOAD_NO_HINTING)
RuntimeError: In set_text: Could not load glyph (error code 0x14)
