Out of curiosity, how does supervised PCA compare to LDA (Linear Discriminant 
Analysis); in a nutshell, what would be the main difference?

Best,
Sebastian

> On Jul 29, 2015, at 5:41 PM, Stylianos Kampakis 
> <stylianos.kampa...@gmail.com> wrote:
> 
> Hi Andreas,
> 
> Sure. Actually, the purpose of the model is both regularization and 
> dimensionality reduction for problems where the number of features can be 
> larger than the number of instances (or in any case when there is a large 
> number of features). It is particularly effective when there are lots of 
> highly correlated attributes with each other.
> 
> L1 regularization breaks down in the presence of lots of correlations. L2 
> deals better with this problem, but ignores the presence of clusters of 
> highly correlated attributes. Supervised PCA is particularly well suited to 
> these kinds of problems. The algorithm seems to outperform partial least 
> squares.
> 
> I actually came up upon this algorithm when trying to find a way to analyze 
> GPS data gathered from the training of a professional football team. Ridge 
> logistic regression didn't provide good results, LASSO either, but supervised 
> PCA worked well. It is also possible to use it to reduce the dimensionality 
> in a way that the components correlate with the response.
> 
> The work was presented at Mathsports International 2015 
> (http://www.mathsportinternational2015.com/uploads/2/2/2/4/22242920/mathsport2015proceedings.pdf
>  
> <http://www.mathsportinternational2015.com/uploads/2/2/2/4/22242920/mathsport2015proceedings.pdf>)
> 
> I am not sure about the popularity of this method, in general, but for me 
> it's going to be one of the standard methods to use in the presence of lots 
> of variables.
> 
> Best regards,
> Stelios
> 
> 2015-07-28 19:16 GMT+01:00 Andreas Mueller <t3k...@gmail.com 
> <mailto:t3k...@gmail.com>>:
> Hi Stylianos.
> 
> Can you give a bit more background on the model?
> It seems fairly well-cited but I haven't really seen it in practice.
> Is it still state of the art?
> The main purpose seems to be a particular type of regularization, right, not 
> supervised dimensionality reduction?
> How does this compare against elastic net? There seems to be some comparison 
> to PLS and lasso in the paper.
> 
> It would be good to see that this is a widely useful method before adding it 
> to sklearn.
> 
> Cheers,
> Andy
> 
> 
> 
> On 07/24/2015 06:40 AM, Stylianos Kampakis wrote:
>> Dear all,
>> 
>> I am thinking to contribute a new model to the library: The supervised 
>> principal components analysis by Bair et al. (2006).
>> 
>> I wanted to get in touch before contributing to make sure no-one else is 
>> working on that algorithm, since this is what the site recommends.
>> 
>> Cheers,
>> S. Kampakis
>> 
>> 
>> ------------------------------------------------------------------------------
>> 
>> 
>> _______________________________________________
>> Scikit-learn-general mailing list
>> Scikit-learn-general@lists.sourceforge.net 
>> <mailto:Scikit-learn-general@lists.sourceforge.net>
>> https://lists.sourceforge.net/lists/listinfo/scikit-learn-general 
>> <https://lists.sourceforge.net/lists/listinfo/scikit-learn-general>
> 
> 
> ------------------------------------------------------------------------------
> 
> _______________________________________________
> Scikit-learn-general mailing list
> Scikit-learn-general@lists.sourceforge.net 
> <mailto:Scikit-learn-general@lists.sourceforge.net>
> https://lists.sourceforge.net/lists/listinfo/scikit-learn-general 
> <https://lists.sourceforge.net/lists/listinfo/scikit-learn-general>
> 
> 
> ------------------------------------------------------------------------------
> _______________________________________________
> Scikit-learn-general mailing list
> Scikit-learn-general@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/scikit-learn-general

------------------------------------------------------------------------------
_______________________________________________
Scikit-learn-general mailing list
Scikit-learn-general@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/scikit-learn-general

Reply via email to