title: plot a graph using coordinates list in python and multiarray error
body: <p>i want to plot graph using a coordinates list like this:</p>
  
  <pre><code>a = [&lt;x1&gt;, &lt;y1&gt;, &lt;x2&gt;, &lt;y2&gt;, …]
  </code></pre>
  
  <p>that is the algorithm that I use:</p>
  
  <pre><code>import matplotlib.pyplot as plt
  import numpy as np
  a = [&lt;x1&gt;, &lt;y1&gt;, &lt;x2&gt;, &lt;y2&gt;, ….]
  x,y = np.array(a).reshape((len(a)/2, 2)).transpose()
  plt.plot(x,y)
  </code></pre>
  
  <p>put i fail with a strange error, the root error is:</p>
  
  <pre><code>ImportError: cannot import name multiarray
  </code></pre>
  
  <p>so what is the problem here. I have to change my algorithm or is there a different way to plot graph using coordinates list.</p>
  
  <p>thanks;</p>
  
  <p>and that is the whole stacktrace:</p>
  
  <pre><code>/usr/bin/python3.3 /cs/usr/mohammadja/grph/graph.py
  Traceback (most recent call last):
    File "/usr/lib/python3/dist-packages/numpy/core/__init__.py", line 16, in &lt;module&gt;
      from . import multiarray
  ImportError: cannot import name multiarray
  
  During handling of the above exception, another exception occurred:
  
  Traceback (most recent call last):
    File "/cs/usr/mohammadja/grph/graph.py", line 1, in &lt;module&gt;
      import matplotlib.pyplot as plt
    File "/usr/lib/python3/dist-packages/matplotlib/__init__.py", line 122, in &lt;module&gt;
      from matplotlib.cbook import is_string_like, mplDeprecation, dedent, get_label
    File "/usr/lib/python3/dist-packages/matplotlib/cbook.py", line 32, in &lt;module&gt;
      import numpy as np
    File "/usr/lib/python3/dist-packages/numpy/__init__.py", line 142, in &lt;module&gt;
      from . import add_newdocs
    File "/usr/lib/python3/dist-packages/numpy/add_newdocs.py", line 13, in &lt;module&gt;
      from numpy.lib import add_newdoc
    File "/usr/lib/python3/dist-packages/numpy/lib/__init__.py", line 8, in &lt;module&gt;
      from .type_check import *
    File "/usr/lib/python3/dist-packages/numpy/lib/type_check.py", line 11, in &lt;module&gt;
      import numpy.core.numeric as _nx
    File "/usr/lib/python3/dist-packages/numpy/core/__init__.py", line 24, in &lt;module&gt;
      raise ImportError(msg)
  ImportError: 
  Importing the multiarray numpy extension module failed.  Most
  likely you are trying to import a failed build of numpy.
  If you're working with a numpy git repo, try `git clean -xdf` (removes all
  files not under version control).  Otherwise reinstall numpy.
  
  
  Process finished with exit code 1
  </code></pre>