statsmodels/statsmodels — pull request #205 by jseabold (2012-03-27 18:29:42+00:00)
Title: dffits fails on Pandas wrapped results

It fails the first time because I think it's trying to broadcast a Series and then return a Series and it fails because it's not 2d. There's a test to replicate it in current master, but the steps are

```python
import statsmodels.api as sm
dta = sm.datasets.longley.load_pandas().data
dta['const'] = 1
res = sm.OLS(dta['TOTEMP'], dta[['const','GNPDEFL', 'GNP', 'UNEMP', 'ARMED',
'POP', 'YEAR']]).fit()

from statsmodels.stats import outliers_influence

infl = outliers_influence.Influence(res)
infl.dffits
```python

I think the quick fix is to just use results._results in the Influence class, which this PR does. Influence could also take advantage of the wrapped results. I think for the most part we're just interested in the results.model._data.row_labels when available and the variable/column names when appropriate.