ValueError: too many values to unpack matplotlib errorbar
<p>I am trying to plot a errorbar:</p>

<pre><code>plt.errorbar(np.array(x_axis), np.array(y_axis), yerr=(np.array(y_bot), np.array(y_top)), linestyle='None', marker='^')
</code></pre>

<p>But it throws an error :</p>

<pre><code>plt.errorbar(np.array(x_axis), np.array(y_axis), yerr=(np.array(y_bot), np.array(y_top)), linestyle='None', marker='^')


File "/Library/Python/2.7/site-packages/matplotlib-1.4.x-py2.7-macosx-10.9-intel.egg/matplotlib/pyplot.py", line 2747, in errorbar
    errorevery=errorevery, capthick=capthick, **kwargs)
  File "/Library/Python/2.7/site-packages/matplotlib-1.4.x-py2.7-macosx-10.9-intel.egg/matplotlib/axes/_axes.py", line 2792, in errorbar
    barcols.append(self.vlines(xo, lo, uo, **lines_kw))
  File "/Library/Python/2.7/site-packages/matplotlib-1.4.x-py2.7-macosx-10.9-intel.egg/matplotlib/axes/_axes.py", line 1067, in vlines
    for thisx, (thisymin, thisymax) in zip(x, Y)]
ValueError: too many values to unpack
</code></pre>

<p>x_axis, y_axis, y_bot, x_bot are 1D array of length 4.</p>