Revisited adjust_interesting_range for parallel::distributed::GridRefinement.

diff --git a/source/distributed/grid_refinement.cc b/source/distributed/grid_refinement.cc
index 3ed69a4ed5e00a3319c70b95b7678ac963d4b31e..2332c92d9d6de0edcd14789d056eeec04fd1ae03 100644 (file)
--- a/source/distributed/grid_refinement.cc
+++ b/source/distributed/grid_refinement.cc
@@ -134,18 +134,30 @@ namespace
   {
     Assert(interesting_range[0] <= interesting_range[1], ExcInternalError());
 
-    Assert(interesting_range[0] >= 0, ExcInternalError());
-
-    // adjust the lower bound only if the end point is not equal to zero,
-    // otherwise it could happen, that the result becomes negative
     if (interesting_range[0] > 0)
-      interesting_range[0] *= 0.99;
-
-    if (interesting_range[1] > 0)
-      interesting_range[1] *= 1.01;
+      {
+        // In this case, we calculate the first interval split point `m` in the
+        // `compute_threshold` functions in the optimized way: We exploit that
+        // the logarithms of all criteria are more uniformly distributed than
+        // their actual values, i.e. m=sqrt(b*e).
+        //
+        // Both factors will modify the split point only slightly by a factor of
+        // sqrt(1.01*0.99) = sqrt(0.9999) ~ 0.9950.
+        interesting_range[0] *= 0.99;
+        interesting_range[1] *= 1.01;
+      }
     else
-      interesting_range[1] +=
-        0.01 * (interesting_range[1] - interesting_range[0]);
+      {
+        // In all other cases, we begin with an the arithmetic mean as the
+        // standard interval split point, i.e. m=(b+e)/2.
+        //
+        // Both increments will add up to zero when calculating the initial
+        // split point in the `compute_threshold` functions.
+        const double difference =
+          std::abs(interesting_range[1] - interesting_range[0]);
+        interesting_range[0] -= 0.01 * difference;
+        interesting_range[1] += 0.01 * difference;
+      }
   }
 
 
@@ -468,8 +480,8 @@ namespace parallel
                                                   tria.n_global_active_cells()),
             mpi_communicator);
 
-        // compute bottom threshold only if necessary. otherwise use a threshold
-        // lower than the smallest value we have locally
+        // compute bottom threshold only if necessary. otherwise use the lowest
+        // threshold possible
         if (adjusted_fractions.second > 0)
           bottom_threshold = dealii::internal::parallel::distributed::
             GridRefinement::RefineAndCoarsenFixedNumber::compute_threshold(
@@ -480,11 +492,7 @@ namespace parallel
                           tria.n_global_active_cells())),
               mpi_communicator);
         else
-          {
-            bottom_threshold =
-              *std::min_element(criteria.begin(), criteria.end());
-            bottom_threshold -= std::fabs(bottom_threshold);
-          }
+          bottom_threshold = std::numeric_limits<Number>::lowest();
 
         // now refine the mesh
         mark_cells(tria, criteria, top_threshold, bottom_threshold);
@@ -535,8 +543,9 @@ namespace parallel
             global_min_and_max,
             top_fraction_of_error * total_error,
             mpi_communicator);
-        // compute bottom threshold only if necessary. otherwise use a threshold
-        // lower than the smallest value we have locally
+
+        // compute bottom threshold only if necessary. otherwise use the lowest
+        // threshold possible
         if (bottom_fraction_of_error > 0)
           bottom_threshold = dealii::internal::parallel::distributed::
             GridRefinement::RefineAndCoarsenFixedFraction::compute_threshold(
@@ -545,11 +554,7 @@ namespace parallel
               (1. - bottom_fraction_of_error) * total_error,
               mpi_communicator);
         else
-          {
-            bottom_threshold =
-              *std::min_element(criteria.begin(), criteria.end());
-            bottom_threshold -= std::fabs(bottom_threshold);
-          }
+          bottom_threshold = std::numeric_limits<Number>::lowest();
 
         // now refine the mesh
         mark_cells(tria, criteria, top_threshold, bottom_threshold);

diff --git a/tests/mpi/tria_ghost_owners_01.mpirun=7.with_p4est=true.output b/tests/mpi/tria_ghost_owners_01.mpirun=7.with_p4est=true.output
index 30c981bfb6f982fe2fbd4e0ba4a24591da9db013..7c9238b44b110f2f06fe2c530c2e79b8213eef94 100644 (file)
--- a/tests/mpi/tria_ghost_owners_01.mpirun=7.with_p4est=true.output
+++ b/tests/mpi/tria_ghost_owners_01.mpirun=7.with_p4est=true.output
@@ -31,7 +31,7 @@ DEAL:0:3d::total active cells = 11702
 DEAL:0:3d::* cycle 3
 DEAL:0:3d::ghost owners: 1 2 
 DEAL:0:3d::level ghost owners: 1 2 
-DEAL:0:3d::total active cells = 37868
+DEAL:0:3d::total active cells = 37833
 DEAL:0:3d::OK
 
 DEAL:1:2d::* cycle 0

diff --git a/tests/mpi/tria_ghost_owners_02.mpirun=11.with_p4est=true.output b/tests/mpi/tria_ghost_owners_02.mpirun=11.with_p4est=true.output
index 59ffd4cb179c9849ac3d86472bc2e94224dec360..bd14c173a85ef4a2d5f04cda4489c07cba746e4e 100644 (file)
--- a/tests/mpi/tria_ghost_owners_02.mpirun=11.with_p4est=true.output
+++ b/tests/mpi/tria_ghost_owners_02.mpirun=11.with_p4est=true.output
@@ -6,15 +6,15 @@ DEAL:0:2d::total active cells = 124
 DEAL:0:2d::* cycle 1
 DEAL:0:2d::ghost owners: 1 2 3 5 6 
 DEAL:0:2d::level ghost owners: 1 2 3 5 6 8 
-DEAL:0:2d::total active cells = 169
+DEAL:0:2d::total active cells = 496
 DEAL:0:2d::* cycle 2
-DEAL:0:2d::ghost owners: 1 2 
-DEAL:0:2d::level ghost owners: 1 2 5 7 
-DEAL:0:2d::total active cells = 190
+DEAL:0:2d::ghost owners: 1 2 3 5 
+DEAL:0:2d::level ghost owners: 1 2 3 5 6 8 
+DEAL:0:2d::total active cells = 733
 DEAL:0:2d::* cycle 3
-DEAL:0:2d::ghost owners: 1 
-DEAL:0:2d::level ghost owners: 1 2 3 6 9 
-DEAL:0:2d::total active cells = 304
+DEAL:0:2d::ghost owners: 1 2 
+DEAL:0:2d::level ghost owners: 1 2 3 5 8 
+DEAL:0:2d::total active cells = 1288
 DEAL:0:2d::OK
 DEAL:0:3d::* cycle 0
 DEAL:0:3d::ghost owners: 2 3 4 6 7 8 10 
@@ -41,11 +41,11 @@ DEAL:1:2d::* cycle 1
 DEAL:1:2d::ghost owners: 0 2 3 5 6 8 
 DEAL:1:2d::level ghost owners: 0 2 3 5 6 8 
 DEAL:1:2d::* cycle 2
-DEAL:1:2d::ghost owners: 0 2 4 
-DEAL:1:2d::level ghost owners: 0 2 4 5 
+DEAL:1:2d::ghost owners: 0 2 3 5 6 8 
+DEAL:1:2d::level ghost owners: 0 2 3 5 6 8 
 DEAL:1:2d::* cycle 3
-DEAL:1:2d::ghost owners: 0 2 3 5 
-DEAL:1:2d::level ghost owners: 0 2 3 5 
+DEAL:1:2d::ghost owners: 0 2 3 
+DEAL:1:2d::level ghost owners: 0 2 3 5 6 
 DEAL:1:2d::OK
 DEAL:1:3d::* cycle 0
 DEAL:1:3d::ghost owners: 
@@ -69,11 +69,11 @@ DEAL:2:2d::* cycle 1
 DEAL:2:2d::ghost owners: 0 1 3 
 DEAL:2:2d::level ghost owners: 0 1 3 5 8 
 DEAL:2:2d::* cycle 2
-DEAL:2:2d::ghost owners: 0 1 3 4 5 7 
-DEAL:2:2d::level ghost owners: 0 1 3 4 5 7 
+DEAL:2:2d::ghost owners: 0 1 3 
+DEAL:2:2d::level ghost owners: 0 1 3 
 DEAL:2:2d::* cycle 3
-DEAL:2:2d::ghost owners: 1 3 6 7 
-DEAL:2:2d::level ghost owners: 0 1 3 5 6 7 9 
+DEAL:2:2d::ghost owners: 0 1 3 4 5 6 8 
+DEAL:2:2d::level ghost owners: 0 1 3 4 5 6 8 
 DEAL:2:2d::OK
 DEAL:2:3d::* cycle 0
 DEAL:2:3d::ghost owners: 0 3 4 6 7 8 10 
@@ -97,11 +97,11 @@ DEAL:3:2d::* cycle 1
 DEAL:3:2d::ghost owners: 0 1 2 4 5 6 8 9 
 DEAL:3:2d::level ghost owners: 0 1 2 4 5 6 8 9 
 DEAL:3:2d::* cycle 2
-DEAL:3:2d::ghost owners: 2 4 
-DEAL:3:2d::level ghost owners: 2 4 
+DEAL:3:2d::ghost owners: 0 1 2 4 6 8 9 
+DEAL:3:2d::level ghost owners: 0 1 2 4 6 8 9 
 DEAL:3:2d::* cycle 3
-DEAL:3:2d::ghost owners: 1 2 4 5 7 9 
-DEAL:3:2d::level ghost owners: 0 1 2 4 5 6 7 9 
+DEAL:3:2d::ghost owners: 1 2 4 5 
+DEAL:3:2d::level ghost owners: 0 1 2 4 5 6 8 9 
 DEAL:3:2d::OK
 DEAL:3:3d::* cycle 0
 DEAL:3:3d::ghost owners: 0 2 4 6 7 8 10 
@@ -125,11 +125,11 @@ DEAL:4:2d::* cycle 1
 DEAL:4:2d::ghost owners: 3 5 8 9 
 DEAL:4:2d::level ghost owners: 3 5 8 9 
 DEAL:4:2d::* cycle 2
-DEAL:4:2d::ghost owners: 1 2 3 5 7 8 
-DEAL:4:2d::level ghost owners: 1 2 3 5 7 8 
+DEAL:4:2d::ghost owners: 3 5 8 9 
+DEAL:4:2d::level ghost owners: 3 5 8 9 
 DEAL:4:2d::* cycle 3
-DEAL:4:2d::ghost owners: 3 5 6 
-DEAL:4:2d::level ghost owners: 3 5 6 
+DEAL:4:2d::ghost owners: 2 3 5 6 8 9 
+DEAL:4:2d::level ghost owners: 2 3 5 6 8 9 
 DEAL:4:2d::OK
 DEAL:4:3d::* cycle 0
 DEAL:4:3d::ghost owners: 0 2 3 6 7 8 10 
@@ -153,11 +153,11 @@ DEAL:5:2d::* cycle 1
 DEAL:5:2d::ghost owners: 0 1 3 4 6 7 9 
 DEAL:5:2d::level ghost owners: 0 1 2 3 4 6 7 8 9 
 DEAL:5:2d::* cycle 2
-DEAL:5:2d::ghost owners: 2 4 6 7 8 
-DEAL:5:2d::level ghost owners: 0 1 2 4 6 7 8 9 
+DEAL:5:2d::ghost owners: 0 1 4 6 7 9 
+DEAL:5:2d::level ghost owners: 0 1 4 6 7 8 9 
 DEAL:5:2d::* cycle 3
-DEAL:5:2d::ghost owners: 1 3 4 6 7 9 
-DEAL:5:2d::level ghost owners: 1 2 3 4 6 7 9 10 
+DEAL:5:2d::ghost owners: 2 3 4 6 8 9 
+DEAL:5:2d::level ghost owners: 0 1 2 3 4 6 7 8 9 
 DEAL:5:2d::OK
 DEAL:5:3d::* cycle 0
 DEAL:5:3d::ghost owners: 
@@ -181,11 +181,11 @@ DEAL:6:2d::* cycle 1
 DEAL:6:2d::ghost owners: 0 1 3 5 7 8 
 DEAL:6:2d::level ghost owners: 0 1 3 5 7 8 10 
 DEAL:6:2d::* cycle 2
-DEAL:6:2d::ghost owners: 5 7 8 9 
-DEAL:6:2d::level ghost owners: 5 7 8 9 
+DEAL:6:2d::ghost owners: 1 3 5 7 8 10 
+DEAL:6:2d::level ghost owners: 0 1 3 5 7 8 10 
 DEAL:6:2d::* cycle 3
-DEAL:6:2d::ghost owners: 2 4 5 7 9 10 
-DEAL:6:2d::level ghost owners: 0 2 3 4 5 7 8 9 10 
+DEAL:6:2d::ghost owners: 2 4 5 7 8 9 
+DEAL:6:2d::level ghost owners: 1 2 3 4 5 7 8 9 
 DEAL:6:2d::OK
 DEAL:6:3d::* cycle 0
 DEAL:6:3d::ghost owners: 0 2 3 4 7 8 10 
@@ -209,11 +209,11 @@ DEAL:7:2d::* cycle 1
 DEAL:7:2d::ghost owners: 5 6 8 10 
 DEAL:7:2d::level ghost owners: 5 6 8 10 
 DEAL:7:2d::* cycle 2
-DEAL:7:2d::ghost owners: 2 4 5 6 8 9 
-DEAL:7:2d::level ghost owners: 0 2 4 5 6 8 9 10 
+DEAL:7:2d::ghost owners: 5 6 8 
+DEAL:7:2d::level ghost owners: 5 6 8 10 
 DEAL:7:2d::* cycle 3
-DEAL:7:2d::ghost owners: 2 3 5 6 8 9 
-DEAL:7:2d::level ghost owners: 2 3 5 6 8 9 10 
+DEAL:7:2d::ghost owners: 6 8 9 
+DEAL:7:2d::level ghost owners: 5 6 8 9 
 DEAL:7:2d::OK
 DEAL:7:3d::* cycle 0
 DEAL:7:3d::ghost owners: 0 2 3 4 6 8 10 
@@ -237,11 +237,11 @@ DEAL:8:2d::* cycle 1
 DEAL:8:2d::ghost owners: 1 3 4 6 7 9 10 
 DEAL:8:2d::level ghost owners: 0 1 2 3 4 5 6 7 9 10 
 DEAL:8:2d::* cycle 2
-DEAL:8:2d::ghost owners: 4 5 6 7 9 10 
-DEAL:8:2d::level ghost owners: 4 5 6 7 9 10 
+DEAL:8:2d::ghost owners: 1 3 4 6 7 9 10 
+DEAL:8:2d::level ghost owners: 0 1 3 4 5 6 7 9 10 
 DEAL:8:2d::* cycle 3
-DEAL:8:2d::ghost owners: 7 9 10 
-DEAL:8:2d::level ghost owners: 6 7 9 10 
+DEAL:8:2d::ghost owners: 2 4 5 6 7 9 10 
+DEAL:8:2d::level ghost owners: 0 2 3 4 5 6 7 9 10 
 DEAL:8:2d::OK
 DEAL:8:3d::* cycle 0
 DEAL:8:3d::ghost owners: 0 2 3 4 6 7 10 
@@ -265,11 +265,11 @@ DEAL:9:2d::* cycle 1
 DEAL:9:2d::ghost owners: 3 4 5 8 10 
 DEAL:9:2d::level ghost owners: 3 4 5 8 10 
 DEAL:9:2d::* cycle 2
-DEAL:9:2d::ghost owners: 6 7 8 10 
-DEAL:9:2d::level ghost owners: 5 6 7 8 10 
+DEAL:9:2d::ghost owners: 3 4 5 8 10 
+DEAL:9:2d::level ghost owners: 3 4 5 8 10 
 DEAL:9:2d::* cycle 3
-DEAL:9:2d::ghost owners: 3 5 6 7 8 10 
-DEAL:9:2d::level ghost owners: 0 2 3 5 6 7 8 10 
+DEAL:9:2d::ghost owners: 4 5 6 7 8 10 
+DEAL:9:2d::level ghost owners: 3 4 5 6 7 8 10 
 DEAL:9:2d::OK
 DEAL:9:3d::* cycle 0
 DEAL:9:3d::ghost owners: 
@@ -293,11 +293,11 @@ DEAL:10:2d::* cycle 1
 DEAL:10:2d::ghost owners: 7 8 9 
 DEAL:10:2d::level ghost owners: 6 7 8 9 
 DEAL:10:2d::* cycle 2
-DEAL:10:2d::ghost owners: 8 9 
-DEAL:10:2d::level ghost owners: 7 8 9 
-DEAL:10:2d::* cycle 3
 DEAL:10:2d::ghost owners: 6 8 9 
-DEAL:10:2d::level ghost owners: 5 6 7 8 9 
+DEAL:10:2d::level ghost owners: 6 7 8 9 
+DEAL:10:2d::* cycle 3
+DEAL:10:2d::ghost owners: 8 9 
+DEAL:10:2d::level ghost owners: 8 9 
 DEAL:10:2d::OK
 DEAL:10:3d::* cycle 0
 DEAL:10:3d::ghost owners: 0 2 3 4 6 7 8