Schematic picture of orbital calculation of pebbles. A planet is located at the origin of the co-rotational frame. The dashed line represents the outer boundary of the hydrodynamical simulations. The starting point of orbital calculation is beyond the outer boundary of hydrodynamical simulations. Its y-component is fixed at 40R_Hill. The initial velocity of the pebble is the same with the Keplerian shear velocity. The gas velocity is assumed to be the speed of the Keplerian shear both inside and outside of r_out in the shear flow case in the Stokes regime (Shear case), but is switched to the gas velocity obtained from the hydrodynamical simulations within r_out in the planet-induced flow case in the Epstein regime (PI-Epstein case), and in the Stokes regime (PI-Stokes case).