function [pos_e, vel_e, Cbn_e, rstat]=AddIniErr(pos, vel, Cbn, errdef, rstat)
%randomize
if (rstat(1)~=0)
randn('state',rstat)
else
rstat=randn('state');
end
if (~isempty(errdef))
pos_e=pos+errdef.pos_sP*randn(3,1);
vel_e=vel+errdef.vel_sP*randn(3,1);
att_e=errdef.att_sP*randn(3,1);
Cerr=euler2dcm_v000(att_e);
Cbn_e=Cerr'*Cbn;
else
pos_e=pos;
vel_e=vel;
Cbn_e=Cbn;
end