Quote:
Originally Posted by Katie C.
When we compute w from the alphas for the softmargin 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
.