Re: [Scikit-learn-general] normalising/scaling input for SVM or Random Forests

2014-03-15 Thread Kevin Keraudren
Thanks a lot for this detailed answer! Kind regards, Kevin Le 14/03/2014 16:37, Olivier Grisel a écrit : > 2014-03-14 15:34 GMT+01:00 Kevin Keraudren : >> Hi, >> >> I have a question related to the range of my input data for SVM or >> Random Forests for classification: >> I normalise my input vec

Re: [Scikit-learn-general] possible bug in LassoCV?

2014-03-15 Thread Joel Nothman
Manoj, perhaps it's worth making sure this has a regression test. On 14 March 2014 17:43, Manoj Kumar wrote: > Yes, I think this has been fixed (intentionally), I remember replacing > alphas by np.sort(alphas), somewhere in the code. > > > On Fri, Mar 14, 2014 at 5:52 AM, Joel Nothman wrote: >

Re: [Scikit-learn-general] GSoC - Completing my Neural Network PRs and more

2014-03-15 Thread Issam
Thanks Olivier, I will upload the proposal very soon. While doing so, I will strengthen my proposal by implementing a basic version of each of the proposed algorithms, which I will cite in my proposal. Cheers. :) On 3/14/2014 5:38 PM, Olivier Grisel wrote: > Issam if I am not mistaken you have

Re: [Scikit-learn-general] normalising/scaling input for SVM or Random Forests

2014-03-15 Thread Satrajit Ghosh
hi olivier, just a question on this statement: Random Forest (and decision tree-based models in general) are scale > independent. > in many cases with fat data (small samples<50 x many features>10) i have found that standardizing helps quite a bit in case of extra trees. i still don't have a

Re: [Scikit-learn-general] normalising/scaling input for SVM or Random Forests

2014-03-15 Thread Gilles Louppe
Hi Satra, In case of Extra-Trees, changing the scale of features might change the result when the transform you apply distorts the original feature space. Drawing a threshold uniformly at random in the original [min;max] interval won't be equivalent to drawing a threshold in [f(min);f(max)] if f i

Re: [Scikit-learn-general] normalising/scaling input for SVM or Random Forests

2014-03-15 Thread Satrajit Ghosh
thanks gilles, that makes sense. i haven't checked random forest classification on these data. i'll check that as well. cheers, satra On Sat, Mar 15, 2014 at 5:51 PM, Gilles Louppe wrote: > Hi Satra, > > In case of Extra-Trees, changing the scale of features might change > the result when th

Re: [Scikit-learn-general] normalising/scaling input for SVM or Random Forests

2014-03-15 Thread Lars Buitinck
2014-03-15 21:53 GMT+01:00 Satrajit Ghosh : > in many cases with fat data (small samples<50 x many features>10) i have > found that standardizing helps quite a bit in case of extra trees. i still > don't have a good understanding as to why this is the case. it could simply > be small sample bia

Re: [Scikit-learn-general] GSoC

2014-03-15 Thread vamsi kaushik
Hi arnaud, Eltermann Thanks for the reply. Firstly I am a noob here so excuse me for any stupid questions. Eltermann Just my 2 cents, I felt your approach(in BestSplitter ) somewhat inefficient when you are calling the get_sparse_item. Firstly even though we have indices of all the non zero items,