diff --git a/swash/processing/post.py b/swash/processing/post.py
index 50cd5e8..2642226 100644
--- a/swash/processing/post.py
+++ b/swash/processing/post.py
@@ -39,13 +39,13 @@ n_t = botl.shape[0]
 t = np.arange(0, n_t * dt, dt)
 
 # Cospectral calculations
-pos_x = config.getint("post", "x0")
+x0 = config.getint("post", "x0")
 t0 = config.getint("post", "t0")
 f = 1 / dt
-log.info(f"Computing reflection coefficient at x={pos_x}")
+log.info(f"Computing reflection coefficient at x={x0}")
 
-eta = (dep - botl)[t > t0, pos_x]
-u = vel[t > t0, 0, pos_x]
+eta = (dep - botl)[t > t0, x0]
+u = vel[t > t0, 0, x0]
 
 phi_eta = np.abs(sgl.csd(eta, eta, f))
 phi_u = np.abs(sgl.csd(u, u, f))
@@ -60,13 +60,13 @@ R = np.sqrt(
 log.info("Plotting results")
 fig, (ax_dep, ax_vel) = plt.subplots(2)
 
-ax_dep.plot(t, (dep - botl)[:, pos_x], label="dep")
+ax_dep.plot(t, (dep - botl)[:, x0], label="dep")
 ax_dep.set(xlabel="t (s)", ylabel="z (m)")
 ax_dep.autoscale(axis="x", tight=True)
 ax_dep.grid()
 ax_dep.axvline(t0, c='k', alpha=.2)
 
-ax_vel.plot(t, vel[:, 0, pos_x], label="vel")
+ax_vel.plot(t, vel[:, 0, x0], label="vel")
 ax_vel.set(xlabel="t (s)", ylabel="U (m/s)")
 ax_vel.autoscale(axis="x", tight=True)
 ax_vel.grid()
@@ -93,8 +93,8 @@ out = pathlib.Path(config.get("post", "out"))
 log.info(f"Saving plots in '{out}'")
 out.mkdir(exist_ok=True)
 
-fig.savefig(out.joinpath(f"t{pos_x}.png"))
-fig_r.savefig(out.joinpath(f"R{pos_x}.png"))
-fig_x.savefig(out.joinpath(f"x{pos_x}.png"))
+fig.savefig(out.joinpath(f"t{x0}.png"))
+fig_r.savefig(out.joinpath(f"R{x0}.png"))
+fig_x.savefig(out.joinpath(f"x{t0}.png"))
 
 log.info("Finished post-processing")