Question

我有以下非常简单的代码：

import matplotlib.pyplot as plt 
import numpy as np
import matplotlib.gridspec as gridspec

x = np.random.randn(60) 
y = np.random.randn(60)
z = [np.random.random() for _ in range(60)]

fig = plt.figure()
gs = gridspec.GridSpec(1, 2)

ax0 = plt.subplot(gs[0, 0])
plt.scatter(x, y, s=20)

ax1 = plt.subplot(gs[0, 1])
cm = plt.cm.get_cmap('RdYlBu_r')
plt.scatter(x, y, s=20 ,c=z, cmap=cm, vmin=0, vmax=1)
cbaxes = fig.add_axes([0.6, 0.12, 0.1, 0.02]) 
plt.colorbar(cax=cbaxes, ticks=[0.,1], orientation='horizontal')

fig.tight_layout()

out_png = '/home/user/image_out.png'
plt.savefig(out_png, dpi=150)
plt.close()

如果我在我的机器上运行它，它会起作用，除了警告：

/usr/local/lib/python2.7/dist-packages/matplotlib/figure.py:1533: UserWarning: This figure includes Axes that are not compatible with tight_layout, so its results might be incorrect.
  warnings.warn("This figure includes Axes that are not "

但是，如果我在群集上运行它，它会退出并出现以下错误：

/usr/lib/pymodules/python2.7/matplotlib/__init__.py:611: UserWarning: Could not find matplotlibrc; using defaults
  warnings.warn('Could not find matplotlibrc; using defaults')
/usr/lib/pymodules/python2.7/matplotlib/__init__.py:698: UserWarning: could not find rc file; returning defaults
  warnings.warn(message)
Traceback (most recent call last):
  File "colorbar.py", line 7, in <module>
    import matplotlib.pyplot as plt 
  File "/usr/lib/pymodules/python2.7/matplotlib/pyplot.py", line 23, in <module>
    from matplotlib.figure import Figure, figaspect
  File "/usr/lib/pymodules/python2.7/matplotlib/figure.py", line 18, in <module>
    from axes import Axes, SubplotBase, subplot_class_factory
  File "/usr/lib/pymodules/python2.7/matplotlib/axes.py", line 14, in <module>
    import matplotlib.axis as maxis
  File "/usr/lib/pymodules/python2.7/matplotlib/axis.py", line 10, in <module>
    import matplotlib.font_manager as font_manager
  File "/usr/lib/pymodules/python2.7/matplotlib/font_manager.py", line 1325, in <module>
    _rebuild()
  File "/usr/lib/pymodules/python2.7/matplotlib/font_manager.py", line 1275, in _rebuild
    fontManager = FontManager()
  File "/usr/lib/pymodules/python2.7/matplotlib/font_manager.py", line 962, in __init__
    paths = [os.path.join(rcParams['datapath'], 'fonts', 'ttf'),
  File "/usr/lib/python2.7/posixpath.py", line 77, in join
    elif path == '' or path.endswith('/'):
AttributeError: 'NoneType' object has no attribute 'endswith'

发生了什么，我该如何解决？

Answer 1

第一个警告与axes和subplots的创建方式有关。创建axes指定大小，而subplots将轴放在常规网格中。

所以tight_layout无法调整axes的大小，就像subplots一样，您会收到警告。因此，在axes

subplots

tight_layout

fig.add_axes([0.6, 0.12, 0.1, 0.02])

在群集上运行时遇到的错误在我看来与matplotlib安装的某些问题有关。警告就是这样：matplotlib在任何standard places中都找不到任何matplotlibrc文件，因此它会回退到默认（硬编码）参数。然后它期望找到参数'datapath'。但是不存在（或错误地定义为None），因此rcParams['datapath']返回None。

然后将参数传递给os.path.join，期望字符串，而不是NoneType。

您可以查看是否getting a matplotlibrc file并放入当前目录或~/.config/matplotlib可以解决您的问题。

您应该做的另一件事是检查matplotlib的版本以及您运行的版本是否是您认为正在使用的版本
```
python -c 'import matplotlib; print(matplotlib.__version__); print(matplotlib.__file__)'
```

ps：我根本不认为你需要gs = gridspec.GridSpec(1, 2)，除非你再用轴做一些额外的事情。如果你这样做，你会得到完全相同的答案

fig = plt.figure(...)
ax0 = fig.add_subplot(121)
ax1 = fig.add_subplot(122)

或

fig, (ax0, ax1) = plt.subplots(nrows=1, ncols=2, ...)

matplotlib错误：UserWarning：找不到rc文件

1 个答案: