title: Unusual axes range for Pandas dataframe plot
body: <p>I'm trying to do simple plotting using the built-in <code>pandas.DataFrame.plot</code> function (I want to avoid the full-blown <code>pyplt</code> figure/axes object setup approach).  However, I get strange results when I don't specify the x-axes range parameter (<code>xlim</code>).  You would think that <code>plot</code> would pick defaults based on the max and min of the data.</p>
  
  <p>(I'm using inline plotting in a Jupyter notebook with Python 2.7)</p>
  
  <p>Setup code</p>
  
  <pre><code>import numpy as np
  import pandas as pd
  
  %matplotlib inline
  n = 366
  x = 10.0*np.random.randn(n)
  
  time_series = pd.date_range("2016-01-01", "2016-12-31")
  df = pd.DataFrame(data=x, index=time_series, columns=['X'])
  df['y'] = 100 + 2.5*x + 5.0*np.random.randn(n)
  df.describe()
  </code></pre>
  
  <p>Here is what the data looks like:</p>
  
  <p><a href="https://i.stack.imgur.com/uJe2z.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/uJe2z.png" alt="enter image description here"></a></p>
  
  <p>Desired code:</p>
  
  <pre><code>df.plot('X', 'y', style='.')
  </code></pre>
  
  <p>Here is what I get from above code:
  <a href="https://i.stack.imgur.com/Y88Fy.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Y88Fy.png" alt="enter image description here"></a></p>
  
  <p>Here is what I expect to get:</p>
  
  <pre><code>df.plot('X', 'y', xlim=(-35, 35), style='.')
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/YF8DF.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/YF8DF.png" alt="enter image description here"></a></p>
  
  <p>Each time I run the code I get an equally-odd choice of default axis range.</p>