我目前正在处理 python+matplotlib+numpy 中的一个莫名其妙的错误。我Ubuntu 13.04 x64在VirtualBox托管Windows 7 pro x64并使用python 2.7（从 Ubuntu 存储库安装）。
考虑以下脚本，该脚本根据名为 的两列文件绘制y函数：xdata.txt
#!/usr/bin/env python
import numpy as np
import matplotlib as mpl
mpl.rcParams['text.usetex']=True
import matplotlib.pyplot as plt
x, y = np.loadtxt("data.txt", unpack=True)
plt.plot(x, y)
plt.show()
并考虑以下事项data.txt：
-49.5938 2.0
-40.6585 0.156267
-39.7351 0.0616373
-39.1767 0.00565121
-38.7736 -0.0346863
-38.4573 -0.0664897
-38.1965 -0.0929013
-37.9744 -0.115588
-37.7809 -0.135542
-37.6093 -0.153403
-37.4551 -0.169605
-37.3151 -0.18446
-37.1868 -0.198198
-37.0684 -0.210994
-36.9584 -0.222983
-36.8722 -0.232458
-36.8228 -0.237918
-36.7749 -0.243232
-36.7284 -0.248409
-36.6833 -0.253457
-36.6395 -0.258382
-36.5968 -0.263192
-36.5553 -0.267892
-36.5149 -0.272489
-36.4754 -0.276987
-36.437 -0.281392
-36.3994 -0.285707
-36.3628 -0.289937
-36.3269 -0.294086
-36.2919 -0.298157
-36.2577 -0.302154
-36.2241 -0.30608
-36.1913 -0.309937
-36.1591 -0.313729
-36.1276 -0.317458
-36.0966 -0.321126
-36.0663 -0.324736
-36.0366 -0.32829
-36.0074 -0.33179
-35.9787 -0.335238
-35.9505 -0.338635
-35.9228 -0.341984
-35.8956 -0.345286
-35.8688 -0.348542
-35.8425 -0.351755
-35.8166 -0.354925
-35.7912 -0.358053
-35.7661 -0.361142
-35.7414 -0.364192
-35.7171 -0.367205
-35.6931 -0.37018
-35.6695 -0.373121
-35.6463 -0.376027
-35.6234 -0.378899
-35.6008 -0.381739
-35.5785 -0.384547
-35.5565 -0.387324
-35.5348 -0.390071
-35.5134 -0.392789
-35.4923 -0.395479
-35.4714 -0.39814
-35.4508 -0.400775
-35.4305 -0.403383
-35.4104 -0.405965
-35.3906 -0.408522
-35.371 -0.411054
-35.3517 -0.413563
-35.3326 -0.416047
-35.3137 -0.418509
-35.295 -0.420948
-35.2765 -0.423366
-35.2582 -0.425762
-35.2402 -0.428137
-35.2223 -0.430491
-35.2047 -0.432825
-35.1872 -0.43514
-35.1699 -0.437435
-35.1528 -0.439711
-35.1358 -0.44197
-35.119 -0.444212
-35.1024 -0.44644
-35.0859 -0.448658
-35.0694 -0.450878
-35.0529 -0.453105
-35.0363 -0.455341
-35.0195 -0.457613
-35.0024 -0.459933
-34.9849 -0.462312
-34.9669 -0.464766
-34.9483 -0.467309
-34.9292 -0.469936
-34.9092 -0.472681
-34.8886 -0.475519
-34.8672 -0.47848
-34.8449 -0.481569
-34.8219 -0.484767
-34.7982 -0.48807
-34.7739 -0.491477
-34.7491 -0.494958
-34.7241 -0.49848
-34.6992 -0.502011
-34.6742 -0.505551
-34.6495 -0.509079
-34.625 -0.512581
-34.6007 -0.516063
-34.5767 -0.519519
-34.553 -0.522941
-34.5296 -0.526332
-34.5065 -0.529692
-34.4837 -0.533017
-34.4612 -0.536311
-34.439 -0.539573
-34.4171 -0.542805
-34.3954 -0.546006
-34.374 -0.549176
-34.3529 -0.552316
-34.3321 -0.555427
-34.3115 -0.55851
-34.2912 -0.561564
-34.2711 -0.564591
-34.2512 -0.567592
-34.2316 -0.570566
-34.2121 -0.573515
-34.193 -0.576439
-34.174 -0.579339
-34.1552 -0.582214
-34.1367 -0.585066
-34.1183 -0.587895
-34.1002 -0.590701
-34.0822 -0.593485
-34.0644 -0.596248
-34.0468 -0.598989
-34.0294 -0.601709
-34.0122 -0.604409
-33.9951 -0.607089
-33.9783 -0.609748
-33.9615 -0.612389
-33.945 -0.615011
-33.9286 -0.617614
-33.9123 -0.620199
-33.8962 -0.622766
-33.8803 -0.625315
-33.8645 -0.627847
-33.8489 -0.630361
-33.8334 -0.632859
-33.818 -0.635341
-33.8028 -0.637806
-33.7877 -0.640256
-33.7727 -0.64269
-33.7579 -0.645108
-33.7432 -0.647511
-33.7286 -0.6499
-33.7141 -0.652274
-33.6998 -0.654634
-33.6856 -0.65698
-33.6714 -0.659315
-33.6574 -0.661635
-33.6435 -0.663947
-33.6297 -0.666249
-33.6159 -0.668547
-33.6022 -0.670835
-33.5885 -0.673127
-33.5749 -0.67542
-33.5612 -0.677726
-33.5475 -0.680025
-33.5338 -0.682341
-33.5201 -0.684666
-33.5062 -0.687017
-33.4923 -0.689387
-33.4782 -0.691796
-33.4639 -0.694247
-33.4494 -0.696723
-33.4347 -0.69924
-33.4199 -0.7018
-33.4047 -0.704414
-33.3893 -0.707087
-33.3737 -0.709791
-33.3578 -0.712549
-33.3418 -0.71534
-33.3255 -0.718181
-33.3091 -0.721056
-33.2924 -0.723999
-33.2755 -0.726975
-33.2585 -0.729988
-33.2412 -0.733045
-33.2237 -0.736152
-33.2061 -0.739295
-33.1884 -0.742461
-33.1706 -0.745656
-33.1525 -0.748904
-33.1344 -0.752172
-33.1162 -0.755459
-33.098 -0.758756
-33.0798 -0.762079
-33.0616 -0.765406
-33.0434 -0.768737
-33.0252 -0.772066
-33.0072 -0.775386
-32.9892 -0.778712
-32.9713 -0.78203
-32.9535 -0.785343
-32.9358 -0.788648
-32.9182 -0.791942
-32.9007 -0.795223
-32.8833 -0.798485
-32.8661 -0.801738
-32.8489 -0.804987
-32.8319 -0.808216
-32.8151 -0.811425
-32.7984 -0.814617
-32.7817 -0.817795
-32.7653 -0.82096
-32.7489 -0.824109
-32.7327 -0.82724
-32.7166 -0.830353
-32.7007 -0.833449
-32.6848 -0.83653
-32.6691 -0.839596
-32.6536 -0.842642
-32.6381 -0.845671
-32.6228 -0.848682
-32.6076 -0.85168
-32.5925 -0.854664
-32.5776 -0.857631
-32.5627 -0.860578
-32.548 -0.863512
-32.5334 -0.866433
-32.5189 -0.869332
-32.5046 -0.872219
-32.4903 -0.87509
-32.4761 -0.877949
-32.4621 -0.880793
-32.4481 -0.883619
-32.4343 -0.886435
-32.4205 -0.889237
-32.4069 -0.892021
-32.3934 -0.894796
-32.3799 -0.897551
-32.3666 -0.900292
-32.3534 -0.903023
-32.3402 -0.905737
-32.3272 -0.908445
-32.3142 -0.911134
-32.3013 -0.913813
-32.2885 -0.916482
-32.2759 -0.919132
-32.2633 -0.921769
-32.2507 -0.924401
-32.2383 -0.92702
-32.2259 -0.929628
-32.2136 -0.932223
-32.2015 -0.934805
-32.1893 -0.937376
-32.1773 -0.939932
-32.1654 -0.942481
-32.1535 -0.94502
-32.1417 -0.947543
-32.13 -0.950056
-32.1183 -0.95256
-32.1068 -0.955052
-32.0952 -0.957536
-32.0838 -0.960005
-32.0725 -0.962469
-32.0612 -0.964924
-32.0499 -0.967368
-32.0387 -0.969807
-32.0276 -0.972236
-32.0165 -0.974663
-32.0055 -0.977076
-31.9946 -0.979485
如果我尝试执行脚本，则会收到以下错误：
Exception in Tkinter callback
Traceback (most recent call last):
File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1473, in __call__
return self.func(*args)
File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_tkagg.py", line 276, in resize
self.show()
File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_tkagg.py", line 348, in draw
FigureCanvasAgg.draw(self)
File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_agg.py", line 440, in draw
self.figure.draw(self.renderer)
File "/usr/lib/pymodules/python2.7/matplotlib/artist.py", line 54, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/figure.py", line 1006, in draw
func(*args)
File "/usr/lib/pymodules/python2.7/matplotlib/artist.py", line 54, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/axes.py", line 2086, in draw
a.draw(renderer)
File "/usr/lib/pymodules/python2.7/matplotlib/artist.py", line 54, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/lib/pymodules/python2.7/matplotlib/axis.py", line 1052, in draw
renderer)
File "/usr/lib/pymodules/python2.7/matplotlib/axis.py", line 1001, in _get_tick_bboxes
extent = tick.label1.get_window_extent(renderer)
File "/usr/lib/pymodules/python2.7/matplotlib/text.py", line 752, in get_window_extent
bbox, info = self._get_layout(self._renderer)
File "/usr/lib/pymodules/python2.7/matplotlib/text.py", line 313, in _get_layout
ismath=ismath)
File "/usr/lib/pymodules/python2.7/matplotlib/backends/backend_agg.py", line 200, in get_text_width_height_descent
renderer=self)
File "/usr/lib/pymodules/python2.7/matplotlib/texmanager.py", line 606, in get_text_width_height_descent
page = next(iter(dvi))
File "/usr/lib/pymodules/python2.7/matplotlib/dviread.py", line 71, in __iter__
have_page = self._read()
File "/usr/lib/pymodules/python2.7/matplotlib/dviread.py", line 126, in _read
byte = ord(self.file.read(1)[0])
IndexError: string index out of range
有趣的是：
-32.0 -1.0如果我用它替换文件的最后两个值- 如果我删除
mpl.rcParams['text.usetex']=True它也可以
如果有人对这个非常奇怪的问题有任何解释，我会非常高兴。