Relative error in the comoving gyroradius (see the right-hand panels of Figures 6 and 7) for ﹩\kappa =10﹩ (left-hand panel) and ﹩\kappa =100﹩ (right-hand panel) calculated by ﹩{R}_{c}=m\gamma ^{\prime} {v}_{\perp }/q| B^{\prime} | ﹩. The relative errors for the Boris scheme and the HC scheme overlap and are indistinguishable here, whereas they result in a different gyromotion in Figure 7.