Relative error in the position for uniform ﹩{\boldsymbol{E}}﹩. The results obtained with the Boris, Vay, and HC schemes are shown with (dashed lines) and without (solid lines) an initial offset. The results for the three explicit leapfrog schemes almost perfectly overlap for both cases with and without an initial offset. The error due to the initial position is clearly pronounced here because within the initial time step, a large Lorentz factor is already reached, given the strong electric field.