title: Python pandas has no attribute ols - Error (rolling OLS)
body: <p>For my evaluation, I wanted to run a rolling 1000 window <code>OLS regression estimation</code> of the dataset found in this URL:
  <a href="https://drive.google.com/open?id=0B2Iv8dfU4fTUa3dPYW5tejA0bzg" rel="noreferrer">https://drive.google.com/open?id=0B2Iv8dfU4fTUa3dPYW5tejA0bzg</a>
  using the following <code>Python</code> script. </p>
  
  <pre><code># /usr/bin/python -tt
  
  import numpy as np
  import matplotlib.pyplot as plt
  import pandas as pd
  from statsmodels.formula.api import ols
  
  df = pd.read_csv('estimated.csv', names=('x','y'))
  
  model = pd.stats.ols.MovingOLS(y=df.Y, x=df[['y']], 
                                 window_type='rolling', window=1000, intercept=True)
  df['Y_hat'] = model.y_predict
  </code></pre>
  
  <p>However, when I run my Python script, I am getting this error: <code>AttributeError: module 'pandas.stats' has no attribute 'ols'</code>. Could this error be from the version that I am using? The <code>pandas</code> installed on my Linux node has a version of <code>0.20.2</code></p>