diff --git a/src/cell.h b/src/cell.h
index 9f35f4386cb161517b1b0c57468f1c0317c0c6a7..b9e060050827e6e0bbd62c87024bbf066d3807f8 100644
--- a/src/cell.h
+++ b/src/cell.h
@@ -152,7 +152,7 @@ struct cell {
double mom[3], ang_mom[3];
/* Mass, potential, internal and kinetic energy of particles in this cell. */
- double mass, e_pot, e_int, e_kin;
+ double mass, e_pot, e_int, e_kin, entropy;
/* Number of particles updated in this cell. */
int updated, g_updated;
diff --git a/src/engine.c b/src/engine.c
index 8e471466fad5bac7c17603a42a59fba50d8c024e..6609f7f0d53453c6649a8089d2b656f555e00f75 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -2098,7 +2098,7 @@ void engine_collect_drift(struct cell *c) {
if (c->drift != NULL) return;
/* Counters for the different quantities. */
- double e_kin = 0.0, e_int = 0.0, e_pot = 0.0, mass = 0.0;
+ double e_kin = 0.0, e_int = 0.0, e_pot = 0.0, entropy = 0.0, mass = 0.0;
double mom[3] = {0.0, 0.0, 0.0}, ang_mom[3] = {0.0, 0.0, 0.0};
/* Only do something is the cell is non-empty */
@@ -2120,6 +2120,7 @@ void engine_collect_drift(struct cell *c) {
e_kin += cp->e_kin;
e_int += cp->e_int;
e_pot += cp->e_pot;
+ entropy += cp->entropy;
mom[0] += cp->mom[0];
mom[1] += cp->mom[1];
mom[2] += cp->mom[2];
@@ -2135,6 +2136,7 @@ void engine_collect_drift(struct cell *c) {
c->e_kin = e_kin;
c->e_int = e_int;
c->e_pot = e_pot;
+ c->entropy = entropy;
c->mom[0] = mom[0];
c->mom[1] = mom[1];
c->mom[2] = mom[2];
@@ -2151,7 +2153,7 @@ void engine_print_stats(struct engine *e) {
const struct space *s = e->s;
- double e_kin = 0.0, e_int = 0.0, e_pot = 0.0, mass = 0.0;
+ double e_kin = 0.0, e_int = 0.0, e_pot = 0.0, entropy = 0.0, mass = 0.0;
double mom[3] = {0.0, 0.0, 0.0}, ang_mom[3] = {0.0, 0.0, 0.0};
/* Collect the cell data. */
@@ -2167,6 +2169,7 @@ void engine_print_stats(struct engine *e) {
e_kin += c->e_kin;
e_int += c->e_int;
e_pot += c->e_pot;
+ entropy += c->entropy;
mom[0] += c->mom[0];
mom[1] += c->mom[1];
mom[2] += c->mom[2];
@@ -2178,8 +2181,8 @@ void engine_print_stats(struct engine *e) {
/* Aggregate the data from the different nodes. */
#ifdef WITH_MPI
{
- double in[10] = {0., 0., 0., 0., 0., 0., 0., 0., 0., 0.};
- double out[10];
+ double in[11] = {0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.};
+ double out[11];
out[0] = e_kin;
out[1] = e_int;
out[2] = e_pot;
@@ -2190,7 +2193,8 @@ void engine_print_stats(struct engine *e) {
out[7] = ang_mom[1];
out[8] = ang_mom[2];
out[9] = mass;
- if (MPI_Allreduce(out, in, 10, MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD) !=
+ out[10] = entropy;
+ if (MPI_Reduce(out, in, 11, MPI_DOUBLE, MPI_SUM, 0, MPI_COMM_WORLD) !=
MPI_SUCCESS)
error("Failed to aggregate stats.");
e_kin = out[0];
@@ -2203,6 +2207,7 @@ void engine_print_stats(struct engine *e) {
ang_mom[1] = out[7];
ang_mom[2] = out[8];
mass = out[9];
+ entropy = out[10];
}
#endif
@@ -2210,10 +2215,11 @@ void engine_print_stats(struct engine *e) {
/* Print info */
if (e->nodeID == 0) {
- fprintf(e->file_stats,
- " %14e %14e %14e %14e %14e %14e %14e %14e %14e %14e %14e %14e\n",
- e->time, mass, e_tot, e_kin, e_int, e_pot, mom[0], mom[1], mom[2],
- ang_mom[0], ang_mom[1], ang_mom[2]);
+ fprintf(
+ e->file_stats,
+ " %14e %14e %14e %14e %14e %14e %14e %14e %14e %14e %14e %14e %14e\n",
+ e->time, mass, e_tot, e_kin, e_int, e_pot, entropy, mom[0], mom[1],
+ mom[2], ang_mom[0], ang_mom[1], ang_mom[2]);
fflush(e->file_stats);
}
}
@@ -2973,10 +2979,11 @@ void engine_init(struct engine *e, struct space *s,
engine_default_energy_file_name);
sprintf(energyfileName + strlen(energyfileName), ".txt");
e->file_stats = fopen(energyfileName, "w");
- fprintf(e->file_stats,
- "# %14s %14s %14s %14s %14s %14s %14s %14s %14s %14s %14s %14s\n",
- "Time", "Mass", "E_tot", "E_kin", "E_int", "E_pot", "p_x", "p_y",
- "p_z", "ang_x", "ang_y", "ang_z");
+ fprintf(
+ e->file_stats,
+ "#%14s %14s %14s %14s %14s %14s %14s %14s %14s %14s %14s %14s %14s\n",
+ "Time", "Mass", "E_tot", "E_kin", "E_int", "E_pot", "Entropy", "p_x",
+ "p_y", "p_z", "ang_x", "ang_y", "ang_z");
fflush(e->file_stats);
char timestepsfileName[200] = "";
diff --git a/src/hydro/Gadget2/hydro.h b/src/hydro/Gadget2/hydro.h
index e998fae3e6078d4fa31141f1b31a3dc037313ada..7ff0ca03997b1526a4d741f31ff02f56bac7f7f1 100644
--- a/src/hydro/Gadget2/hydro.h
+++ b/src/hydro/Gadget2/hydro.h
@@ -282,3 +282,15 @@ __attribute__((always_inline)) INLINE static float hydro_get_internal_energy(
return entropy * pow_gamma_minus_one(p->rho) * hydro_one_over_gamma_minus_one;
}
+
+/**
+ * @brief Returns the entropy of a particle
+ *
+ * @param p The particle of interest
+ * @param dt Time since the last kick
+ */
+__attribute__((always_inline)) INLINE static float hydro_get_entropy(
+ const struct part *restrict p, float dt) {
+
+ return p->entropy + p->entropy_dt * dt;
+}
diff --git a/src/runner.c b/src/runner.c
index e48d2ccaba69315f4295a0dbacd36e9c7d26a0c4..e845d29288ecbd2b0d76587b42555c3777639864 100644
--- a/src/runner.c
+++ b/src/runner.c
@@ -593,7 +593,7 @@ void runner_do_drift(struct runner *r, struct cell *c, int timer) {
struct gpart *restrict gparts = c->gparts;
float dx_max = 0.f, dx2_max = 0.f, h_max = 0.f;
- double e_kin = 0.0, e_int = 0.0, e_pot = 0.0, mass = 0.0;
+ double e_kin = 0.0, e_int = 0.0, e_pot = 0.0, entropy = 0.0, mass = 0.0;
double mom[3] = {0.0, 0.0, 0.0};
double ang_mom[3] = {0.0, 0.0, 0.0};
@@ -670,6 +670,9 @@ void runner_do_drift(struct runner *r, struct cell *c, int timer) {
e_kin += 0.5 * m * (v[0] * v[0] + v[1] * v[1] + v[2] * v[2]);
e_pot += 0.;
e_int += m * hydro_get_internal_energy(p, half_dt);
+
+ /* Collect entropy */
+ entropy += hydro_get_entropy(p, half_dt);
}
/* Now, get the maximal particle motion from its square */
@@ -694,6 +697,7 @@ void runner_do_drift(struct runner *r, struct cell *c, int timer) {
e_kin += cp->e_kin;
e_int += cp->e_int;
e_pot += cp->e_pot;
+ entropy += cp->entropy;
mom[0] += cp->mom[0];
mom[1] += cp->mom[1];
mom[2] += cp->mom[2];
@@ -710,6 +714,7 @@ void runner_do_drift(struct runner *r, struct cell *c, int timer) {
c->e_kin = e_kin;
c->e_int = e_int;
c->e_pot = e_pot;
+ c->entropy = entropy;
c->mom[0] = mom[0];
c->mom[1] = mom[1];
c->mom[2] = mom[2];