2011/12/6 Vlad Niculae <[email protected]>:
> On Tue, Dec 6, 2011 at 11:46 PM, Alexandre Gramfort
> <[email protected]> wrote:
>> I do confirm that Lasso and LassoLars both minimize
>>
>> 1/2n || y - Xw || + alpha ||w||_1
>>
>> and that the n should not be present in the sparse coding context.
>>
>> it means :
>>
>> http://scikit-learn.org/stable/modules/linear_model.html#lasso
>>
>> is not correct. I don't know if this also affects the doc of the SGD.
>> I would also vote for writing the cost function minimized in the Lasso
>> (etc.) docstrings.
>>
>> regarding the shapes using sparse_encode I'll let Vlad comment.
>
> At first sight I agree with Olivier re: the shapes. The alpha issue is
> a semantics one and we should simply multiply it back by the
> appropriate dimension in order to expose a  clear interface.
>
> How about I address these issues in the pull request I opened earlier today?

+1, also make it possible to expose the ability to up the max_iter of
LARS from the sparse_encode API as reported by Ian.

> I just remember discussing with Alex that the alpha values for the
> MiniBatch versions of the algorithms didn't correspond to the batch
> versions. I now realize that this might be the reason; the scaling for
> a mini-batch was different than for the full batch.

Indeed.

-- 
Olivier
http://twitter.com/ogrisel - http://github.com/ogrisel

------------------------------------------------------------------------------
Cloud Services Checklist: Pricing and Packaging Optimization
This white paper is intended to serve as a reference, checklist and point of 
discussion for anyone considering optimizing the pricing and packaging model 
of a cloud services business. Read Now!
http://www.accelacomm.com/jaw/sfnl/114/51491232/
_______________________________________________
Scikit-learn-general mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/scikit-learn-general

Reply via email to