Hi Andy, according to [1] "The multiclass support is handled according to a one-vs-one scheme." That's why I was using the wrapper. For now I am doing multi-class single-label, although that might change in the future. Maybe it is not the MetaEstimatorMixin that needs fixing but just the docs? :P
Best /Daan [1]: http://scikit-learn.org/stable/modules/generated/sklearn.svm.SVC.html On 11/09/15 16:43, Andreas Mueller wrote: > Hi Daan. > This looks like a bug, please open a pull request. > Are you doing multi-label classification? For multi-class, SVC already > has built-in OvR support. > > Best, > Andy > > > On 09/11/2015 04:17 AM, Daan Wynen wrote: >> Hi all, >> >> I recently was in the position of wanting to use a OneVsRest SVC for ~50 >> classes. >> It turned out that this was not easily possible with sklearn because the >> GridSearchCV class queries the classifier's _pairwise property to see if >> the data is a square matrix and should be sliced in both dimensions or >> if it is a matrix that only needs to be sliced in the first dimension. >> >> What works for me is adding these lines to the MetaEstimatorMixin in >> ./base.py: >> >> class MetaEstimatorMixin(object): >> """Mixin class for all meta estimators in scikit-learn.""" >> >> @property >> def _pairwise(self): >> # Used by cross_val_score. >> return getattr(self.estimator, "_pairwise", False) >> >> >> OneVsRestClassifier uses this mixin which so far was just a flag. >> Now it takes the property from the wrapped class. >> Is there a good reason why this was not the case before?Any pitfalls I >> don't see coming at the moment? >> >> Thanks for your input >> /Daan >> >> >> ------------------------------------------------------------------------------ >> _______________________________________________ >> 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 ------------------------------------------------------------------------------ _______________________________________________ Scikit-learn-general mailing list Scikit-learn-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/scikit-learn-general
