From: nethaji anandhavalli on
S(:,k)=0;
From: Wayne King on
"nethaji anandhavalli" <mydreamprojects(a)yahoo.com> wrote in message <hqkntq$sj8$1(a)fred.mathworks.com>...
> S(:,k)=0;

Set all the rows of S in the k-th column to 0.