function [ rk ] = findLargestinCol( A,k )
% findLargestinCol: find the row index of the large element in column k
%    (of some matrix A)
  [value,index] = max( abs( A(:,k) ) );  % max is built-in for matlab
                                         % don't forget to take absolute
                                         % value
  rk = index;
end

