PyTorch MMDDrift kernel not being sent to device

[ascillitoe]

The MMDDriftTorch detector's kernel attribute is not sent to the correct device. See this comment.

The following:

self.kernel = kernel(sigma) if kernel == GaussianRBF else kernel

should be changed to:

self.kernel = kernel(sigma).to(self.device) if kernel == GaussianRBF else kernel

[ascillitoe]

@jklaise do you think we should release a patch for this?

[jklaise]

@ascillitoe probably since the next release would be at least a few weeks away. I was assuming it's a genuine bug, but weird that not spotted before @arnaudvl

[arnaudvl]

Yes definitely a genuine bug, was very surprised when I ran into it during the KeOps PR. Worthy of a patch release I think.

[ascillitoe]

OK I shall do this today 👍🏻

Also agree its weird that we didn't spot it earlier. I assume the kernel was being implicity copied over to device when called or something? Maybe we'll see a speedup now!