This is a basic question on the meaning of the following notation. Can someone explain how I would evaluate the Summation forumula below? And perhaps point me to a reference where I can understand how to evaluate?
I am assuming that we are trying to determine max value of S which is part of the set {-1 to 1} where i iterates from 1 to d?
$h(\mathbf x) = \sum_{i=1}^d \max_{s \in \{1,-1\}} s x_i$
Very odd notation, seems to mean the sum of mod $x_i$ i.e for each term in the sum we want the max of ${-x_i,x_i}$ i.e if $x_i$ is positive we add $x_i$ and if $x_i$ is negative we add $-x_i$ (which is a positive term.