Schematic picture of an 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 40 R_Hill (Ida & Nakazawa 1989). The x- and z-coordinates of the starting point of pebbles, x_s and z_s, are the parameters. The gas velocity is assumed to be the speed of the sub-Keplerian shear both inside and outside of r_out in the shear flow case of the unperturbed flow (UP-mXX-hwYY case), but is switchedto the gas velocity obtained from the hydrodynamical simulations within r_out in the planet-induced flow case in the Epstein regime (PI-Epstein-mXX-hwYY case), and in the Stokes regime (PI-Stokes-mXX-hwYY case).