Hi.
Afaik VC dimension is mostly of theoretical interest and not of much practical value as the bounds tend to be very lose.
If you have any practical application, I would be interested.

VC dimension is a property of a class of hypotheses, so it is nothing that refers to the parameter that you estimated but rather to the
class that you consider for fitting.
So it doesn't really make sense to write any code.
Basically for all linear classifiers you can return n_features + 1 for example. For the rbf SVM you can give a formular in terms of gamma and the diameter of the data. I'm sure for naive bayes there is an easy formular, too, while decision trees have a VC dimension that is basically the number of leaves you allow. Not sure the VC dimension for random forests is known
in any meaningful way.
The VC dimension of KNN is inverse proportional to n_neighbors, though the precise formula eludes me.

Btw, there are stronger bounds for some classifiers. For example there are margin-based bounds for SVMs (I think they might even be implemented in the svm module?), that are independent of the feature dimension.

Hth,
procrastinating Andy


On 03/13/2013 03:32 PM, ShNaYkHs ShNaYkHs wrote:
Hello all,

Is it possible to get the VC dimension (Vapnik--Chervonenkis dimension) of the supervised classifiers of sklearn ? Do someone know how or if it is actually possible to add this utility to sklearn ? The VC dimension is a pretty important utility, since it can predict an upper bound on the test error of a classification model (without doing the test ...).
http://en.wikipedia.org/wiki/VC_dimension

Best,
ShNaYkHs.



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