Re: [Scikit-learn-general] Code contribution: Supervised PCA

2015-07-30 Thread Stylianos Kampakis
Sorry, my fault. Supervised PCA is different to Linear Discriminant Analysis. It uses a heuristic to keep only the variables that show some correlation with the response when calculating the components. It does not incorporate explicitly the class separation as an objective. Supervised PCA can be

Re: [Scikit-learn-general] Code contribution: Supervised PCA

2015-07-30 Thread Mathieu Blondel
He was asking about Linear Discriminant Analysis, not Latent Dirichlet Allocation. Mathieu On Thu, Jul 30, 2015 at 7:58 PM, Stylianos Kampakis < stylianos.kampa...@gmail.com> wrote: > Hi Sebastian, > > LDA is unsupervised. Supervised PCA finds components correlated with the > response variable.

Re: [Scikit-learn-general] Code contribution: Supervised PCA

2015-07-30 Thread Stylianos Kampakis
Hi Sebastian, LDA is unsupervised. Supervised PCA finds components correlated with the response variable. Best regards, Stelios 2015-07-29 22:55 GMT+01:00 Sebastian Raschka : > Out of curiosity, how does supervised PCA compare to LDA (Linear > Discriminant Analysis); in a nutshell, what would b

Re: [Scikit-learn-general] Code contribution: Supervised PCA

2015-07-30 Thread Stylianos Kampakis
My feeling is that it will perform better in cases where there are clusters of correlated attributes, which the exact same case where it would make sense to use a dimensionality reduction technique such as factor analysis or PCA. Hastie et al. in their book "Elements of Statistical Learning" propo

Re: [Scikit-learn-general] Code contribution: Supervised PCA

2015-07-29 Thread Sebastian Raschka
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 > wrote: > > Hi Andreas, > > Sure. Actually, the purpose of the model is both regulariz

Re: [Scikit-learn-general] Code contribution: Supervised PCA

2015-07-29 Thread Andreas Mueller
Indeed it sounds interesting but I'd still be curious as to how it compares against elasticnet. On 07/29/2015 05:41 PM, Stylianos Kampakis wrote: Hi Andreas, Sure. Actually, the purpose of the model is both regularization and dimensionality reduction for problems where the number of features

Re: [Scikit-learn-general] Code contribution: Supervised PCA

2015-07-29 Thread Stylianos Kampakis
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

Re: [Scikit-learn-general] Code contribution: Supervised PCA

2015-07-28 Thread Andreas Mueller
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 compar

[Scikit-learn-general] Code contribution: Supervised PCA

2015-07-24 Thread Stylianos Kampakis
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 --