Removed h_max from the YAML file. Users can now specify a maximal number of top-level cells.

examples/parameter_example.yml

@@ -8,11 +8,12 @@ InternalUnitSystem:
 
 # Parameters for the task scheduling
 Scheduler:
-  nr_queues:        0        # (Optional) The number of task queues to use. Use 0  to let the system decide.
-  cell_max_size:    8000000  # (Optional) Maximal number of interactions per task if we force the split (this is the default value).
-  cell_sub_size:    64000000 # (Optional) Maximal number of interactions per sub-task  (this is the default value).
-  cell_split_size:  400      # (Optional) Maximal number of particles per cell (this is the default value).
-  cell_max_count:   10000    # (Optional) Maximal number of particles per cell allowed before triggering a sanitizing (this is the default value).
+  nr_queues:             0        # (Optional) The number of task queues to use. Use 0  to let the system decide.
+  cell_max_size:         8000000  # (Optional) Maximal number of interactions per task if we force the split (this is the default value).
+  cell_sub_size:         64000000 # (Optional) Maximal number of interactions per sub-task  (this is the default value).
+  cell_split_size:       400      # (Optional) Maximal number of particles per cell (this is the default value).
+  cell_max_count:        10000    # (Optional) Maximal number of particles per cell allowed before triggering a sanitizing (this is the default value).
+  max_top_level_cells:   12       # (Optional) Maximal number of top-level cells per dimension. The number of top-level cells will be the cube of this.
 
 # Parameters governing the time integration
 TimeIntegration:
@@ -43,9 +44,8 @@ Statistics:
 SPH:
   resolution_eta:        1.2348   # Target smoothing length in units of the mean inter-particle separation (1.2348 == 48Ngbs with the cubic spline kernel).
   delta_neighbours:      0.1      # The tolerance for the targetted number of neighbours.
-  max_ghost_iterations:  30       # (Optional) Maximal number of iterations allowed to converge towards the smoothing length.
-  max_smoothing_length:  0.1      # Maximal smoothing length allowed (in internal units).
   CFL_condition:         0.1      # Courant-Friedrich-Levy condition for time integration.
+  max_ghost_iterations:  30       # (Optional) Maximal number of iterations allowed to converge towards the smoothing length.
   max_volume_change:     2.       # (Optional) Maximal allowed change of kernel volume over one time-step
 
 # Parameters related to the initial conditions

src/space.c

@@ -1738,6 +1738,7 @@ void space_init(struct space *s, const struct swift_params *params,
   s->dim[0] = dim[0];
   s->dim[1] = dim[1];
   s->dim[2] = dim[2];
+  const double dmax = max(max(dim[0], dim[1]), dim[2]);
   s->periodic = periodic;
   s->gravity = gravity;
   s->nr_parts = Npart;
@@ -1746,7 +1747,9 @@ void space_init(struct space *s, const struct swift_params *params,
   s->nr_gparts = Ngpart;
   s->size_gparts = Ngpart;
   s->gparts = gparts;
-  s->cell_min = parser_get_param_double(params, "SPH:max_smoothing_length");
+  s->cell_min =
+      dmax / parser_get_opt_param_int(params, "Scheduler:max_top_level_cells",
+                                      space_max_top_level_cells_default);
   s->nr_queues = 1; /* Temporary value until engine construction */
 
   /* Get the constants for the scheduler */

src/space.h

@@ -42,6 +42,7 @@
 #define space_maxsize_default 8000000
 #define space_subsize_default 64000000
 #define space_maxcount_default 10000
+#define space_max_top_level_cells_default 12
 #define space_stretch 1.10f
 #define space_maxreldx 0.25f