Dear Mohammadjavad, This kind of questions are best directed to the scikit-learn mailing list (and I am forwarding it there). In this case, as the preimage is just the inverse transformation between spaces, I don't think it would make much sense to use a different kernel, so I guess it will be the same one. But I'm not the best person to ask, I've never even used the Kernel PCA.
Cheers, Vlad ---------- Forwarded message ---------- From: Vlad Niculae <[email protected]> Date: Mon, Nov 25, 2013 at 10:41 PM Subject: Fwd: Problem with scikit learn kernel PCA To: Vlad Niculae <[email protected]> On Mon, Nov 25, 2013 at 9:47 PM, Mohammadjavad Vakili <[email protected]> wrote: > Dear Vlad, > > I am currently using the function "inverse_transform" in the kernel PCA > module and I'm not sure what exactly it does. In the documentation it says > this is an implementation of "Learning to find the pre-image"(Bakir etal > 2004). > > But my problem is that in the paper they do not specify what the kernel > (\kappa) they use for learning the pre-image. In scikit learn > implementation, is that kernel the same kernel (K) used for transformation > from the original data to the feature space? > > Thanks a lot, > -Mohammadjavad ------------------------------------------------------------------------------ Shape the Mobile Experience: Free Subscription Software experts and developers: Be at the forefront of tech innovation. Intel(R) Software Adrenaline delivers strategic insight and game-changing conversations that shape the rapidly evolving mobile landscape. Sign up now. http://pubads.g.doubleclick.net/gampad/clk?id=63431311&iu=/4140/ostg.clktrk _______________________________________________ Scikit-learn-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/scikit-learn-general
