Better documentation of the initial and minimal temperature setting in the hydro properties.

src/hydro_properties.c

@@ -93,7 +93,7 @@ void hydro_props_init(struct hydro_props *p,
   p->initial_temperature = parser_get_opt_param_float(
       params, "SPH:initial_temperature", hydro_props_default_init_temp);
 
-  /* Initial temperature */
+  /* Minimal temperature */
   p->minimal_temperature = parser_get_opt_param_float(
       params, "SPH:minimal_temperature", hydro_props_default_min_temp);
 
@@ -106,11 +106,12 @@ void hydro_props_init(struct hydro_props *p,
       params, "SPH:H_mass_fraction", hydro_props_default_H_fraction);
 
   /* Compute the initial energy (Note the temp. read is in internal units) */
+  /* u_init = k_B T_init / (mu m_p (gamma - 1)) */
   double u_init = phys_const->const_boltzmann_k / phys_const->const_proton_mass;
   u_init *= p->initial_temperature;
   u_init *= hydro_one_over_gamma_minus_one;
 
-  /* Correct for hydrogen mass fraction */
+  /* Correct for hydrogen mass fraction (mu) */
   double mean_molecular_weight;
   if (p->initial_temperature *
           units_cgs_conversion_factor(us, UNIT_CONV_TEMPERATURE) >
@@ -122,11 +123,12 @@ void hydro_props_init(struct hydro_props *p,
   p->initial_internal_energy = u_init / mean_molecular_weight;
 
   /* Compute the minimal energy (Note the temp. read is in internal units) */
+  /* u_min = k_B T_min / (mu m_p (gamma - 1)) */
   double u_min = phys_const->const_boltzmann_k / phys_const->const_proton_mass;
   u_min *= p->minimal_temperature;
   u_min *= hydro_one_over_gamma_minus_one;
 
-  /* Correct for hydrogen mass fraction */
+  /* Correct for hydrogen mass fraction (mu) */
   if (p->minimal_temperature *
           units_cgs_conversion_factor(us, UNIT_CONV_TEMPERATURE) >
       1e4)
@@ -135,14 +137,6 @@ void hydro_props_init(struct hydro_props *p,
     mean_molecular_weight = 4. / (1. + 3. * p->hydrogen_mass_fraction);
 
   p->minimal_internal_energy = u_min / mean_molecular_weight;
-
-#ifdef PLANETARY_SPH
-#ifdef PLANETARY_SPH_BALSARA
-  message("Planetary SPH: Balsara switch enabled");
-#else
-  message("Planetary SPH: Balsara switch disabled");
-#endif  // PLANETARY_SPH_BALSARA
-#endif  // PLANETARY_SPH
 }
 
 /**
@@ -184,6 +178,15 @@ void hydro_props_print(const struct hydro_props *p) {
 
   if (p->minimal_temperature != hydro_props_default_min_temp)
     message("Minimal gas temperature set to %f", p->minimal_temperature);
+
+  // Matthieu: Temporary location for this i/o business.
+#ifdef PLANETARY_SPH
+#ifdef PLANETARY_SPH_BALSARA
+  message("Planetary SPH: Balsara switch enabled");
+#else
+  message("Planetary SPH: Balsara switch disabled");
+#endif  // PLANETARY_SPH_BALSARA
+#endif  // PLANETARY_SPH
 }
 
 #if defined(HAVE_HDF5)