/** # Box-boundary values are not set consistently Here the quadtree version is demonstrated. The bottom-left ghost cell has a value of `s = 5`, However, on a multigrid (or Cartesian grid) it becomes `s = 1`. I wish it was 3? ~~~gnuplot Values and their locations set xr [-0.3:0.6] set yr [-0.3:0.6] set size square set key off plot 'log' w l lw 2, 'out' u 1:2:3 w labels ~~~ */ //#include "grid/multigrid.h" // <- uncomment for MG scalar s[]; s[left] = dirichlet (2.); s[bottom] = dirichlet (2.); int main() { init_grid (4); foreach() s[] = 1.; output_cells (stderr); foreach() foreach_neighbor(1) printf ("%g %g %g\n", x, y, s[]); }