%
% * ``k`` - the value of k when we stop; i.e. the number of
% iterations.
+ %
+ % NOTES:
+ %
+ % A specialized implementation for solving e.g. Qx=b can avoid one
+ % matrix-vector multiplication below.
+ %
% The initial gradient at x_{0} is not supplied, so we compute it
% here and begin the loop at k=1.