private static void draw_gridmap(PLStream pl, int nw, int cmap0_offset) { double vmin = 0.0, vmax = 1.0; for (int i = 0; i < nw; i++) { pl.col0(i + cmap0_offset); pl.adv(0); pl.vpor(vmin, vmax, vmin, vmax); pl.wind(vmin, vmax, vmin, vmax); plfbox(pl); } }