














• 
If we map the
input vectors into a very highdimensional


feature space,
surely the task of finding the maximum



margin separator
becomes computationally intractable?




– 
The
mathematics is all linear, which is good, but the



vectors
have a huge number of components.




– 
So
taking the scalar product of two vectors is very



expensive.



• 
The way to keep
things tractable is to use



“the
kernel trick”



• 
The kernel trick
makes your brain hurt when you first



learn about it,
but its actually very simple.

