View Single Post
#2
05-24-2013, 05:31 PM
 yaser Caltech Join Date: Aug 2009 Location: Pasadena, California, USA Posts: 1,478
Re: computing w, b for soft margin SVM

Quote:
 Originally Posted by Katie C. When we compute w from the alphas for the soft-margin SVM which values of alpha do we include? only margin support vectors ( those with 0 < alpha_n < C)? or do we include all of them (0 < alpha_n <= C)? Similarly, when computing b, can we use any support vector? or only margin support vectors?
1. All of them for computing , since any vector with will contribute to the derived solution for .

2. Only margin SV's for computing , since we need an equation, not an inequality, to solve for after knowing .
__________________
Where everyone thinks alike, no one thinks very much