Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-13 Thread Jaques Grobler
I updated the gist with the example in __main__ to create the plots as in http://www2.isye.gatech.edu/statistics/papers/05-25.pdf, figure 1. Bon weekend J 2012/4/11 Jaques Grobler > haha okay, I'll give it a swing! > > J > > > 2012/4/11 Alexandre Gramfort > >> > The simulations that are done i

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-11 Thread Jaques Grobler
haha okay, I'll give it a swing! J 2012/4/11 Alexandre Gramfort > > The simulations that are done in the last mentioned paper by Ming Yuan > and > > Yi Lin, > > http://www2.isye.gatech.edu/statistics/papers/05-25.pdf, they find > that the > > NG seems to do > > generally better than the LASSO

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-11 Thread Alexandre Gramfort
> The simulations that are done in the last mentioned paper by Ming Yuan and > Yi Lin, > http://www2.isye.gatech.edu/statistics/papers/05-25.pdf,  they find that the > NG seems to do > generally better than the LASSO (figure 1) if you can reproduce this figure using my gist I pay you a beer :) I

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-11 Thread Jaques Grobler
@Olivier - no problem :) @Alex Appart from trying it ourselves to see how it fares, here're some findings: The simulations that are done in the last mentioned paper by Ming Yuan and Yi Lin, http://www2.isye.gatech.edu/statistics/papers/05-25.pdf, they find that the NG seems to do generally bette

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-11 Thread Olivier Grisel
Le 11 avril 2012 11:53, Alexandre Gramfort a écrit : > > it seems to me that it might be a good addition to the scikit if can > convince ourselves with examples that it does better than a Lasso. I agree. Thanks for the write-up Jacques. -- Olivier http://twitter.com/ogrisel - http://github.com

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-11 Thread Alexandre Gramfort
> The algorithm proposed in this paper, is rather similar to that of the  Lars > LASSO, but with a complicating > factor being a non-negative constraint on the shrinkage factor. (See eq. (2) > in this paper) > Once you've computed  your shrinkage factor, you basically have your > regression coeffic

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-11 Thread Jaques Grobler
Here's a wee summary on the non-negative garrote (NG) i pieced together: The original non-negative garrote from Breiman (1995) is basically a scaled version of the least square estimate. Basically take a OLS estimator and then shrink that estimator to obtain a more sparse representation. The shrin

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-10 Thread Alexandre Gramfort
> Does it give it extra consistency properties? e.g. unbiased estimates? could be … Jaques will explain this to us tomorrow :) He's watching the talk on video-lectures :) Alex -- Better than sec? Nothing is better than

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-10 Thread Mathieu Blondel
To continue with funny algorithm names, can we have the top moumoute online natural gradient algorithm in scikit-learn :) ? http://nicolas.le-roux.name/publications/LeRoux08_tonga.pdf Mathieu -- Better than sec? Nothing i

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-10 Thread Gael Varoquaux
On Tue, Apr 10, 2012 at 02:52:04PM +0200, Alexandre Gramfort wrote: > it has a rescaling step like Adaptive Lasso but using OLS. The > positivity is just to impose the same sign of in coef_ and coef_ as > obtained with OLS Does it give it extra consistency properties? e.g. unbiased estimates? G

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-10 Thread Alexandre Gramfort
> Yes, basically the non-negative garrote is a non-negative Lasso, if I > understand it correctly. Thus if your priors are that your model is > sparse, and with only positive weights, the non-negative garrote is the > right estimator. no :) it has a rescaling step like Adaptive Lasso but using OL

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-10 Thread Gael Varoquaux
On Tue, Apr 10, 2012 at 02:44:56PM +0200, Jaques Grobler wrote: >This paper mentions >We also show that the nonnegative garrote has the nice property that >with probability tending to one, the solution path contains an >estimate that correctly identi es the set of important variable

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-10 Thread Alexandre Gramfort
> What the benefit of non-negative Garotte? unclear to me for now. I'm still reading on the topic. But if somebody can pitch in I'm interested. Alex -- Better than sec? Nothing is better than sec when it comes to monitor

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-10 Thread Jaques Grobler
hahaha @Olivier 's Garotte cake This paper mentions We also show that the nonnegative garrote has the nice property that with probability tending to one, the solution path contains an estimate that correctly identi es the set of important variables and is consis- tent for the coecients of the im

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-10 Thread Gael Varoquaux
> > What the benefit of non-negative Garotte? > To cook a non-negative Garotte cake? Definitely tastier than a negative Garotte cake. -- Better than sec? Nothing is better than sec when it comes to monitoring Big Data ap

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-10 Thread Olivier Grisel
Le 10 avril 2012 14:39, Gael Varoquaux a écrit : > What the benefit of non-negative Garotte? To cook a non-negative Garotte cake? -- Olivier http://twitter.com/ogrisel - http://github.com/ogrisel -- Better than sec? No

Re: [Scikit-learn-general] Non-Negative Garotte

2012-04-10 Thread Gael Varoquaux
What the benefit of non-negative Garotte? G -- Better than sec? Nothing is better than sec when it comes to monitoring Big Data applications. Try Boundary one-second resolution app monitoring today. Free. http://p.sf.net

[Scikit-learn-general] Non-Negative Garotte

2012-04-10 Thread Alexandre Gramfort
hi, as soon as we have Immanuel's branch with positive lasso [1] merged we could have a non-negative Garotte in the scikit. A quick gist (hopefully not too buggy): https://gist.github.com/2351057 Feed back welcome and if someone is willing to cleanly merge this … Alex PS: I've added the snippe