here is the PR https://github.com/scikit-learn/scikit-learn/pull/438
Alex On Fri, Nov 11, 2011 at 3:53 AM, Gael Varoquaux <[email protected]> wrote: > On Thu, Nov 10, 2011 at 09:58:16PM -0500, Alexandre Gramfort wrote: >> To me this is wrong to not apply such a scaling by n_samples. To >> motivate this, just look as the gist and you will see that if you don't >> do it then C / alpha needs to be changed if you duplicate every sample. >> This is particularly problematic with the cross-validation as you end >> up finding a C/alpha adapted to the size of the training folds rather >> than the full data. Think about the refit in GridSearchCV. > >> Let me know what you think but I feel we should fix this. > > Yes, we should fix this, but we are breaking backward compatibility by > doing this. Thus people will scratch there head and look at their results > wondering why hell broke loose when they updated their version of the > scikit. > > Thus we need to plan a way forward for these changes: > > 1. I think that we should add a parameter to the different objects that > we are changing, that sets the scaling behavior. For one release or > two, the parameter is set by default in such a way that the behavior > is not changed. After this, we change the default, and yet-again > after a couple release, we remove it. > > 2. We need a warning that things will change in a later release and the > the right way to follow these changes is to switch the value of the > parameter. > > 3. We need a clear statement in whats_new.rst > > 4. Maybe we need to have a file for internal use where we document the > future changes, so that we don't forget this (and other things). > > My 2 cents, > > Gaël > > ------------------------------------------------------------------------------ > RSA(R) Conference 2012 > Save $700 by Nov 18 > Register now > http://p.sf.net/sfu/rsa-sfdev2dev1 > _______________________________________________ > Scikit-learn-general mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/scikit-learn-general > ------------------------------------------------------------------------------ RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 _______________________________________________ Scikit-learn-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/scikit-learn-general
