Thread: Q9, SVM vs PLA
View Single Post
  #10  
Old 05-22-2013, 12:16 PM
Elroch Elroch is offline
Invited Guest
 
Join Date: Mar 2013
Posts: 143
Default Re: Q9, SVM vs PLA

Quote:
Originally Posted by jlaurentum View Post
Elroch:
I didn't plot the solutions obtained by ipop because on seeing that the insample error was not zero, that invalidated everything for me. What parameters did you use for ipop?
You may have seen a clue from the plot. I recall it helped me.

Essentially, I used the recipe in the R documentation page for ipop, except after a bit of experimentation I changed the value of H to kernelPol(vanilladot(),x,,y) and played about with the cost (I'm still not sure about that - anyone able to clarify?)

I should point out that (possibly due to not being at all familiar with ipop) I wrote a chunk of code to get the hypothesis needed for comparison. Basically it constructed the weight vector from the alphas and the support vectors as described in the lecture, calculated the values of the dot products on all of the support vectors, and then adjusted the first parameter of the weight vector so that the zero line was right in the middle of the support vectors. The main help of visualisation was seeing that the right points were support vectors. I am guessing there is probably a way to do this more directly (by doing the dual?)
Reply With Quote