diff --git a/src/engine.c b/src/engine.c
index cbf0d36d5c7a33cf520f1de6ae6a8b86a9de4180..47bee144b6f6d245003da2ca2955502ba1dc9c68 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -4200,7 +4200,8 @@ void engine_init_particles(struct engine *e, int flag_entropy_ICs,
message("Performing Friends Of Friends search.");
- /* Calculate the particle linking length based upon the mean inter-particle spacing. */
+ /* Calculate the particle linking length based upon the mean inter-particle
+ * spacing. */
const int total_nr_dmparts = e->total_nr_gparts - e->total_nr_parts;
const double l_x = 0.2 * (s->dim[0] / cbrt(total_nr_dmparts));
s->l_x2 = l_x * l_x;
diff --git a/src/fof.c b/src/fof.c
index 3e41f038660ca9e7415dae0e0aacfbe51c7b689a..fbe773cf5f0b1c6538fb62db3165778c9a549115 100644
--- a/src/fof.c
+++ b/src/fof.c
@@ -83,16 +83,15 @@ __attribute__((always_inline)) INLINE static double cell_min_dist(
/* Recurse on a cell and perform a FOF search between cells that are within
* range. */
static void rec_fof_search_sub(struct cell *ci, struct cell *cj,
- struct space *s, int *pid, int *num_in_groups,
- int *num_groups, const double *dim,
- const double search_r2) {
+ struct space *s, int *pid, int *num_groups,
+ const double *dim, const double search_r2) {
/* Recurse on cj. */
if (cj->split)
for (int k = 0; k < 8; k++)
if (cj->progeny[k] != NULL)
- rec_fof_search_sub(ci, cj->progeny[k], s, pid, num_in_groups,
- num_groups, dim, search_r2);
+ rec_fof_search_sub(ci, cj->progeny[k], s, pid, num_groups, dim,
+ search_r2);
/* No progeny? */
if (!cj->split) {
@@ -107,7 +106,7 @@ static void rec_fof_search_sub(struct cell *ci, struct cell *cj,
/* Perform FOF search between pairs of cells that are within the linking
* length and not the same cell. */
if (r2 < search_r2 && ci != cj) {
- fof_search_pair_cells(s, ci, cj, pid, num_in_groups, num_groups);
+ fof_search_pair_cells(s, ci, cj, pid, num_groups);
}
}
}
@@ -116,15 +115,14 @@ static void rec_fof_search_sub(struct cell *ci, struct cell *cj,
* cells. Recurse on top-level cells that are within range and perform a FOF
* search between cells. */
static void rec_fof_search(struct cell *ci, const int cid, struct space *s,
- int *pid, int *num_in_groups, int *num_groups,
- const double *dim, const double search_r2) {
+ int *pid, int *num_groups, const double *dim,
+ const double search_r2) {
/* Recurse on ci. */
if (ci->split)
for (int k = 0; k < 8; k++)
if (ci->progeny[k] != NULL)
- rec_fof_search(ci->progeny[k], cid, s, pid, num_in_groups, num_groups,
- dim, search_r2);
+ rec_fof_search(ci->progeny[k], cid, s, pid, num_groups, dim, search_r2);
/* No progeny? */
if (!ci->split) {
@@ -133,7 +131,7 @@ static void rec_fof_search(struct cell *ci, const int cid, struct space *s,
const double ciz = ci->loc[2];
/* Perform FOF search on local particles within the cell. */
- fof_search_cell(s, ci, pid, num_in_groups, num_groups);
+ fof_search_cell(s, ci, pid, num_groups);
/* Loop over all top-level cells skipping over the cells already searched.
*/
@@ -151,12 +149,11 @@ static void rec_fof_search(struct cell *ci, const int cid, struct space *s,
if (r2 > search_r2)
continue;
else if (cj->split)
- rec_fof_search_sub(ci, cj, s, pid, num_in_groups, num_groups, dim,
- search_r2);
+ rec_fof_search_sub(ci, cj, s, pid, num_groups, dim, search_r2);
/* Perform FOF search between pairs of cells that are within the linking
* length and not the same cell. */
else if (ci != cj)
- fof_search_pair_cells(s, ci, cj, pid, num_in_groups, num_groups);
+ fof_search_pair_cells(s, ci, cj, pid, num_groups);
}
}
}
@@ -185,7 +182,7 @@ void fof_search_serial(struct space *s) {
if (posix_memalign((void **)&num_in_groups, 32, nr_gparts * sizeof(int)) != 0)
error("Failed to allocate list of number in groups for FOF search.");
- for (size_t i = 0; i < nr_gparts; i++) num_in_groups[i] = 1;
+ for (size_t i = 0; i < nr_gparts; i++) num_in_groups[i] = 0;
/* Loop over particles and find which particles belong in the same group. */
for (size_t i = 0; i < nr_gparts; i++) {
@@ -224,21 +221,19 @@ void fof_search_serial(struct space *s) {
/* Hit or miss? */
if (r2 < l_x2) {
- if (root_j < root_i) {
+ if (root_j < root_i)
pid[root_i] = root_j;
- num_in_groups[root_j] += num_in_groups[root_i];
- num_in_groups[root_i] -= num_in_groups[root_i];
- } else {
+ else
pid[root_j] = root_i;
- num_in_groups[root_i] += num_in_groups[root_j];
- num_in_groups[root_j] -= num_in_groups[root_j];
- }
num_groups--;
}
}
}
+ /* Calculate the total number of particles in each group. */
+ for (size_t i = 0; i < nr_gparts; i++) num_in_groups[fof_find(i, pid)]++;
+
fof_dump_group_data("fof_output_serial.dat", nr_gparts, pid, num_in_groups);
int num_parts_in_groups = 0;
@@ -264,7 +259,7 @@ void fof_search_serial(struct space *s) {
/* Perform a FOF search on a single cell using the Union-Find algorithm.*/
void fof_search_cell(struct space *s, struct cell *c, int *pid,
- int *num_in_groups, int *num_groups) {
+ int *num_groups) {
const size_t count = c->gcount;
struct gpart *gparts = c->gparts;
@@ -310,15 +305,10 @@ void fof_search_cell(struct space *s, struct cell *c, int *pid,
/* Hit or miss? */
if (r2 < l_x2) {
- if (root_j < root_i) {
+ if (root_j < root_i)
pid[root_i] = root_j;
- num_in_groups[root_j] += num_in_groups[root_i];
- num_in_groups[root_i] -= num_in_groups[root_i];
- } else {
+ else
pid[root_j] = root_i;
- num_in_groups[root_i] += num_in_groups[root_j];
- num_in_groups[root_j] -= num_in_groups[root_j];
- }
(*num_groups)--;
}
@@ -328,7 +318,7 @@ void fof_search_cell(struct space *s, struct cell *c, int *pid,
/* Perform a FOF search on a pair of cells using the Union-Find algorithm.*/
void fof_search_pair_cells(struct space *s, struct cell *ci, struct cell *cj,
- int *pid, int *num_in_groups, int *num_groups) {
+ int *pid, int *num_groups) {
const size_t count_i = ci->gcount;
const size_t count_j = cj->gcount;
@@ -391,15 +381,10 @@ void fof_search_pair_cells(struct space *s, struct cell *ci, struct cell *cj,
/* Hit or miss? */
if (r2 < l_x2) {
- if (root_j < root_i) {
+ if (root_j < root_i)
pid[root_i] = root_j;
- num_in_groups[root_j] += num_in_groups[root_i];
- num_in_groups[root_i] -= num_in_groups[root_i];
- } else {
+ else
pid[root_j] = root_i;
- num_in_groups[root_i] += num_in_groups[root_j];
- num_in_groups[root_j] -= num_in_groups[root_j];
- }
(*num_groups)--;
}
@@ -434,7 +419,7 @@ void fof_search_tree_serial(struct space *s) {
if (posix_memalign((void **)&num_in_groups, 32, nr_gparts * sizeof(int)) != 0)
error("Failed to allocate list of number in groups for FOF search.");
- for (size_t i = 0; i < nr_gparts; i++) num_in_groups[i] = 1;
+ for (size_t i = 0; i < nr_gparts; i++) num_in_groups[i] = 0;
/* Loop over cells and find which cells are in range of each other to perform
* the FOF search. */
@@ -446,9 +431,12 @@ void fof_search_tree_serial(struct space *s) {
fflush(stdout);
/* Recursively perform FOF search on all other cells in top-level grid. */
- rec_fof_search(c, cid, s, pid, num_in_groups, &num_groups, dim, search_r2);
+ rec_fof_search(c, cid, s, pid, &num_groups, dim, search_r2);
}
+ /* Calculate the total number of particles in each group. */
+ for (size_t i = 0; i < nr_gparts; i++) num_in_groups[fof_find(i, pid)]++;
+
fof_dump_group_data("fof_output_tree_serial.dat", nr_gparts, pid,
num_in_groups);
diff --git a/src/fof.h b/src/fof.h
index c0804d5499ec45a577542b4f0e536757c25e4c15..0d470ad05c40f1e9064fb709e479b533dded89cb 100644
--- a/src/fof.h
+++ b/src/fof.h
@@ -30,9 +30,9 @@
/* Function prototypes. */
void fof_search_serial(struct space *s);
void fof_search_cell(struct space *s, struct cell *c, int *pid,
- int *num_in_groups, int *num_groups);
+ int *num_groups);
void fof_search_pair_cells(struct space *s, struct cell *ci, struct cell *cj,
- int *pid, int *num_in_groups, int *num_groups);
+ int *pid, int *num_groups);
void fof_search_tree_serial(struct space *s);
void fof_dump_group_data(char *out_file, const size_t nr_gparts, int *pid,
int *num_in_groups);