egs: add higher-order finite difference operatorstmp

1 files changed, 3 insertions, 1 deletions

diff --git a/mg2d.c b/mg2d.c
index 11a8158..b4a9124 100644
--- a/mg2d.c
+++ b/mg2d.c
@@ -224,7 +224,7 @@ static int mg_solve_subgrid(MG2DContext *ctx, MG2DLevel *level)
 finish:
     res_new = level->solver->residual_max;
     if (!isfinite(res_new) ||
-        (res_new > 1e2 * DBL_EPSILON && res_old / res_new <= 1e-1)) {
+        (res_new > 1e2 * DBL_EPSILON && res_old / res_new <= 1e-2)) {
         mg2di_log(&ctx->priv->logger, MG2D_LOG_ERROR,
                   "The relaxation step at level %d has diverged: %g -> %g\n",
                   level->depth, res_old, res_new);
@@ -399,6 +399,8 @@ static int mg_levels_init(MG2DContext *ctx)
             switch (ctx->fd_stencil) {
             case 1: op_interp = GRID_TRANSFER_LAGRANGE_3; break;
             case 2: op_interp = GRID_TRANSFER_LAGRANGE_5; break;
+            case 3: op_interp = GRID_TRANSFER_LAGRANGE_7; break;
+            case 4: op_interp = GRID_TRANSFER_LAGRANGE_7; break;
             default: return -ENOSYS;
             }