Add SGD

SGD Classifier and Regressor added

The default parameters are:

```python
'alpha': [0.000001, 0.00001, 0.0001, 0.001, 0.01], 'penalty': ['l1', 'l2', 'elasticnet']
```
Hi,

I have corrected that error.

Hope that now works.

From: Dan Blanchard [mailto:notifications@github.com]
Sent: Wednesday, June 11, 2014 9:21 AM
To: EducationalTestingService/skll
Cc: Murrugarra Llerena, Nils E
Subject: Re: [skll] Add SGD (#118)


In tests/configs/test_sparse.template.cfg:

> @@ -6,7 +6,7 @@ task=evaluate

>  train_location=

>  test_location=

>  featuresets=[["test_sparse"]]

> -learners=['LogisticRegression', 'LinearSVC', 'SVC', 'MultinomialNB', 'DecisionTreeClassifier', 'RandomForestClassifier', 'GradientBoostingClassifier']

> +learners=['LogisticRegression', 'LinearSVC', 'SVC', 'MultinomialNB', 'DecisionTreeClassifier', 'RandomForestClassifier', 'GradientBoostingClassifier', 'SGDClassifier'']

You've got an extra ' at the end of this line before the ] that is causing this unit test to fail. Take that out and everything should be fine, I think.

—
Reply to this email directly or view it on GitHub<https://github.com/EducationalTestingService/skll/pull/118/files#r13647841>.

________________________________

This e-mail and any files transmitted with it may contain privileged or confidential information. It is solely for use by the individual for whom it is intended, even if addressed incorrectly. If you received this e-mail in error, please notify the sender; do not disclose, copy, distribute, or take any action in reliance on the contents of this information; and delete it from your system. Any other use of this e-mail is prohibited.


Thank you for your compliance.

________________________________