tk_agg plotting error when using legend()

Adam_Ginsburg · September 17, 2009, 8:28pm

Hi, I'm running into the following error:

findfont: Matching
:family=sans-serif:style=normal:variant=normal:weight=normal:stretch=normal:size=medium
to Bitstream Vera Sans (/usr/X11R6/lib/X11/fonts/TTF/Vera.ttf) with
score of 0.000000
Found dvipng version 1.11
findfont: Matching
:family=sans-serif:style=normal:variant=normal:weight=normal:stretch=normal:size=large
to Bitstream Vera Sans (/usr/X11R6/lib/X11/fonts/TTF/Vera.ttf) with
score of 0.000000
Exception in Tkinter callback
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/lib-tk/Tkinter.py",
line 1410, in __call__
    return self.func(*args)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_tkagg.py",
line 212, in resize
    self.show()
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_tkagg.py",
line 215, in draw
    FigureCanvasAgg.draw(self)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_agg.py",
line 388, in draw
    self.figure.draw(self.renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
    draw(artist, renderer, *kl)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/figure.py",
line 772, in draw
    for a in self.axes: a.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
    draw(artist, renderer, *kl)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/axes.py",
line 1760, in draw
    a.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
    draw(artist, renderer, *kl)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/legend.py",
line 389, in draw
    self._legend_box.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
    c.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
    c.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
    c.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
    c.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 504, in draw
    c.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
    draw(artist, renderer, *kl)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/lines.py",
line 530, in draw
    drawFunc(renderer, gc, tpath, affine.frozen())
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/lines.py",
line 866, in _draw_lines
    self._lineFunc(renderer, gc, path, trans)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/lines.py",
line 917, in _draw_dashed
    renderer.draw_path(gc, path, trans)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_agg.py",
line 117, in draw_path
    self._renderer.draw_path(gc, path, transform, rgbFace)
TypeError: float() argument must be a string or a number
Exception in Tkinter callback
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/lib-tk/Tkinter.py",
line 1410, in __call__
    return self.func(*args)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_tkagg.py",
line 212, in resize
    self.show()
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_tkagg.py",
line 215, in draw
    FigureCanvasAgg.draw(self)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_agg.py",
line 388, in draw
    self.figure.draw(self.renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
    draw(artist, renderer, *kl)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/figure.py",
line 772, in draw
    for a in self.axes: a.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
    draw(artist, renderer, *kl)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/axes.py",
line 1760, in draw
    a.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
    draw(artist, renderer, *kl)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/legend.py",
line 389, in draw
    self._legend_box.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
    c.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
    c.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
    c.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
    c.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 504, in draw
    c.draw(renderer)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
    draw(artist, renderer, *kl)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/lines.py",
line 530, in draw
    drawFunc(renderer, gc, tpath, affine.frozen())
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/lines.py",
line 866, in _draw_lines
    self._lineFunc(renderer, gc, path, trans)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/lines.py",
line 917, in _draw_dashed
    renderer.draw_path(gc, path, trans)
  File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_agg.py",
line 117, in draw_path
    self._renderer.draw_path(gc, path, transform, rgbFace)
TypeError: float() argument must be a string or a number

Using the following code:
from pylab import *
import numpy,scipy,matplotlib;
h=6.626e-27
c=3e10
nu=3e18/5500.
k=1.38e-16
T=6000
mynu=linspace(1e13,10**15.2,100000)
dnu = mean(mynu[1:]-mynu[:-1])
planck = 2*h*mynu**3/c**2 * (exp(h*mynu/(k*T))-1)**-1
mylam=linspace(1500e-8,5e-4,100000)
dlam = mean(mylam[1:]-mylam[:-1])
planckL=2*h*c**2/mylam**5*(exp(h*c/(mylam*k*T))-1)**-1; planckLn =
planckL* planck.max()/planckL.max()
figure(0); clf(); loglog(mynu,planck,label=r'$\nu$')
plot(3e10/mylam,planckLn,label=r'$\lambda$')
xlabel(r'$\nu$')
ylabel(r'$B_\nu$')
vlines(3e10/5500e-8,1e-7,1e-4)
vlines(3e10/6000e-8,1e-7,1e-4,linestyle='--')
vlines(3e10/5000e-8,1e-7,1e-4,linestyle='--')
legend(loc='best')

figure(1); clf()
loglog(mynu,planck*mynu,label=r'$\nu$')
plot(3e10/mylam,planckL*mylam,label=r'$\lambda$')
vlines(3e10/5500e-8,1e6,2e10)
vlines(3e10/6000e-8,1e6,2e10,linestyle='--')
vlines(3e10/5000e-8,1e6,2e10,linestyle='--')
xlabel(r'$\nu = c / \lambda$')
ylabel(r'$\nu B_\nu = \lambda B_\lambda$')
legend(loc='best')

lamlow = 5000e-8
lamhi = 6000e-8
nulow = 3e10/lamhi
nuhi = 3e10/lamlow
whnu = (mynu<nuhi)*(mynu>nulow)
whlam = (mylam<lamhi)*(mylam>lamlow)
int_nu = (planck[whnu]*dnu).sum()
int_lam = (planckL[whlam]*dlam).sum()

print "int_nu = %g" % (int_nu)
print "int_lam = %g" % (int_lam)

show()

The error only happens when I use a legend; i.e. there is no error
when the legend() lines are commented out. I've only explored a
little parameter space but it still happens without latex in the
labels and when I use a linear-linear plot.

Adam

_Jae-Joon_Lee1 · September 17, 2009, 10:03pm

This turned out to be a bug in the legend code. This is now fixed in
the maint. branch and the trunk.

Adam,
Do you want these vertical lines show up in the legend?
If not, the easiest workaround is to use some garbage label which
starts with "_", i.e.,

vlines(3e10/6000e-8,1e-7,1e-4,linestyle='--', label="_nolabel")

If you want, you may use axvline or plot instead, which creates a
Line2D instance (instead of LineCollection) which will work fine with
the legend.

Regards,

-JJ

···

On Thu, Sep 17, 2009 at 4:28 PM, Adam Ginsburg <adam.ginsburg@...179...> wrote:

Hi, I'm running into the following error:

findfont: Matching
:family=sans-serif:style=normal:variant=normal:weight=normal:stretch=normal:size=medium
to Bitstream Vera Sans (/usr/X11R6/lib/X11/fonts/TTF/Vera.ttf) with
score of 0.000000
Found dvipng version 1.11
findfont: Matching
:family=sans-serif:style=normal:variant=normal:weight=normal:stretch=normal:size=large
to Bitstream Vera Sans (/usr/X11R6/lib/X11/fonts/TTF/Vera.ttf) with
score of 0.000000
Exception in Tkinter callback
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/lib-tk/Tkinter.py",
line 1410, in __call__
return self.func(*args)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_tkagg.py",
line 212, in resize
self.show()
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_tkagg.py",
line 215, in draw
FigureCanvasAgg.draw(self)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_agg.py",
line 388, in draw
self.figure.draw(self.renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
draw(artist, renderer, *kl)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/figure.py",
line 772, in draw
for a in self.axes: a.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
draw(artist, renderer, *kl)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/axes.py",
line 1760, in draw
a.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
draw(artist, renderer, *kl)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/legend.py",
line 389, in draw
self._legend_box.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
c.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
c.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
c.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
c.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 504, in draw
c.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
draw(artist, renderer, *kl)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/lines.py",
line 530, in draw
drawFunc(renderer, gc, tpath, affine.frozen())
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/lines.py",
line 866, in _draw_lines
self._lineFunc(renderer, gc, path, trans)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/lines.py",
line 917, in _draw_dashed
renderer.draw_path(gc, path, trans)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_agg.py",
line 117, in draw_path
self._renderer.draw_path(gc, path, transform, rgbFace)
TypeError: float() argument must be a string or a number
Exception in Tkinter callback
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/lib-tk/Tkinter.py",
line 1410, in __call__
return self.func(*args)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_tkagg.py",
line 212, in resize
self.show()
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_tkagg.py",
line 215, in draw
FigureCanvasAgg.draw(self)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_agg.py",
line 388, in draw
self.figure.draw(self.renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
draw(artist, renderer, *kl)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/figure.py",
line 772, in draw
for a in self.axes: a.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
draw(artist, renderer, *kl)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/axes.py",
line 1760, in draw
a.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
draw(artist, renderer, *kl)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/legend.py",
line 389, in draw
self._legend_box.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
c.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
c.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
c.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 240, in draw
c.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/offsetbox.py",
line 504, in draw
c.draw(renderer)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/artist.py",
line 55, in draw_wrapper
draw(artist, renderer, *kl)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/lines.py",
line 530, in draw
drawFunc(renderer, gc, tpath, affine.frozen())
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/lines.py",
line 866, in _draw_lines
self._lineFunc(renderer, gc, path, trans)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/lines.py",
line 917, in _draw_dashed
renderer.draw_path(gc, path, trans)
File "/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/matplotlib/backends/backend_agg.py",
line 117, in draw_path
self._renderer.draw_path(gc, path, transform, rgbFace)
TypeError: float() argument must be a string or a number

Using the following code:
from pylab import *
import numpy,scipy,matplotlib;
h=6.626e-27
c=3e10
nu=3e18/5500.
k=1.38e-16
T=6000
mynu=linspace(1e13,10**15.2,100000)
dnu = mean(mynu[1:]-mynu[:-1])
planck = 2*h*mynu**3/c**2 * (exp(h*mynu/(k*T))-1)**-1
mylam=linspace(1500e-8,5e-4,100000)
dlam = mean(mylam[1:]-mylam[:-1])
planckL=2*h*c**2/mylam**5*(exp(h*c/(mylam*k*T))-1)**-1; planckLn =
planckL* planck.max()/planckL.max()
figure(0); clf(); loglog(mynu,planck,label=r'\\nu')
plot(3e10/mylam,planckLn,label=r'\\lambda')
xlabel(r'\\nu')
ylabel(r'B\_\\nu')
vlines(3e10/5500e-8,1e-7,1e-4)
vlines(3e10/6000e-8,1e-7,1e-4,linestyle='--')
vlines(3e10/5000e-8,1e-7,1e-4,linestyle='--')
legend(loc='best')

figure(1); clf()
loglog(mynu,planck*mynu,label=r'\\nu')
plot(3e10/mylam,planckL*mylam,label=r'\\lambda')
vlines(3e10/5500e-8,1e6,2e10)
vlines(3e10/6000e-8,1e6,2e10,linestyle='--')
vlines(3e10/5000e-8,1e6,2e10,linestyle='--')
xlabel(r'\\nu = c / \\lambda')
ylabel(r'\\nu B\_\\nu = \\lambda B\_\\lambda')
legend(loc='best')

lamlow = 5000e-8
lamhi = 6000e-8
nulow = 3e10/lamhi
nuhi = 3e10/lamlow
whnu = (mynu<nuhi)*(mynu>nulow)
whlam = (mylam<lamhi)*(mylam>lamlow)
int_nu = (planck[whnu]*dnu).sum()
int_lam = (planckL[whlam]*dlam).sum()

print "int_nu = %g" % (int_nu)
print "int_lam = %g" % (int_lam)

show()

The error only happens when I use a legend; i.e. there is no error
when the legend() lines are commented out. I've only explored a
little parameter space but it still happens without latex in the
labels and when I use a linear-linear plot.

Adam

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