The numerical simulations of the dark–bright solitons with small noise: (a) for dark-soliton component and (b) for bright-soliton component. The initial excitation conditions are given by the same parameters as in Fig. 6 at t = −0.5 by multiplying a factor (1 + 0.02 Random[−1,1]). It is seen that the dark–bright solitons are robust against small noise.