title: AttributeError: 'numpy.ndarray' object has no attribute 'columns' when trying to plot coefficients
body: <p>I'm trying to plot coefficients from my means model and am getting this error: AttributeError: 'numpy.ndarray' object has no attribute 'columns'</p>
  <p>My code was originally</p>
  <pre><code>xvals = X2.columns[1:]
  </code></pre>
  <p>After realizing that arrays don't have columns, they have values, I changed it to .values instead, but got the error: AttributeError: 'numpy.ndarray' object has no attribute 'values'.</p>
  <p>So I did some research and saw that I needed(I think) to add either loc or .iloc to it, so I finished with the below code and get the following error 'numpy.ndarray' object has no attribute 'iloc' or loc, depending which one I use. Any ideas?</p>
  <pre><code>xvals = X2.loc[1:].values
  
  coeffs =np.exp(reg.coef_[0])-1.0
  
  plot.figure(figsize=(10,5))
  plot.bar(xvals, coeffs)
  plot.xticks(rotation=90)
  plot.ylabel(&quot;Coefficients [a.u.]&quot;)
  plot.show()
  </code></pre>