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Commit c0d32233 authored by Matthieu Schaller's avatar Matthieu Schaller
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Removed the softened isothermal potential. The isothermal potential is now... 

Removed the softened isothermal potential. The isothermal potential is now softened by default. Set epsilon to 0 to restore the old behaviour.
parent e8c2ac7a
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configure.ac
View file @ c0d32233
......@@ -766,9 +766,6 @@ case "$with_potential" in
isothermal)
AC_DEFINE([EXTERNAL_POTENTIAL_ISOTHERMAL], [1], [Isothermal external potential])
;;
softened-isothermal)
AC_DEFINE([EXTERNAL_POTENTIAL_SOFTENED_ISOTHERMAL], [1], [Softened isothermal external potential])
;;
disc-patch)
AC_DEFINE([EXTERNAL_POTENTIAL_DISC_PATCH], [1], [Disc-patch external potential])
;;
......
examples/CoolingHalo/cooling_halo.yml
View file @ c0d32233
......@@ -37,7 +37,7 @@ InitialConditions:
shift_z: 0.
# External potential parameters
SoftenedIsothermalPotential:
IsothermalPotential:
position_x: 0. # location of centre of isothermal potential in internal units
position_y: 0.
position_z: 0.
......
examples/CoolingHaloWithSpin/cooling_halo.yml
View file @ c0d32233
......@@ -34,7 +34,7 @@ InitialConditions:
file_name: CoolingHalo.hdf5 # The file to read
# External potential parameters
SoftenedIsothermalPotential:
IsothermalPotential:
position_x: 0. # location of centre of isothermal potential in internal units
position_y: 0.
position_z: 0.
......
examples/HydrostaticHalo/hydrostatic.yml
View file @ c0d32233
......@@ -34,7 +34,7 @@ InitialConditions:
file_name: Hydrostatic.hdf5 # The file to read
# External potential parameters
SoftenedIsothermalPotential:
IsothermalPotential:
position_x: 0. # location of centre of isothermal potential in internal units
position_y: 0.
position_z: 0.
......
examples/parameter_example.yml
View file @ c0d32233
......@@ -81,15 +81,7 @@ IsothermalPotential:
position_z: 100.
vrot: 200. # Rotation speed of isothermal potential (internal units)
timestep_mult: 0.03 # Dimensionless pre-factor for the time-step condition
# External potential parameters
SoftenedIsothermalPotential:
position_x: 0. # Location of centre of isothermal potential with respect to centre of the box (internal units)
position_y: 0.
position_z: 0.
vrot: 200. # rotation speed of isothermal potential (internal units)
epsilon: 0.1 # Softening size (internal units)
timestep_mult: 0.03 # controls time step
# Disk-patch potential parameters
DiscPatchPotential:
......
src/Makefile.am
View file @ c0d32233
......@@ -79,7 +79,6 @@ nobase_noinst_HEADERS = align.h approx_math.h atomic.h cycle.h error.h inline.h
riemann/riemann_exact.h riemann/riemann_vacuum.h \
potential/none/potential.h potential/point_mass/potential.h \
potential/isothermal/potential.h potential/disc_patch/potential.h \
potential/softened_isothermal/potential.h \
cooling/none/cooling.h cooling/none/cooling_struct.h \
cooling/const_du/cooling.h cooling/const_du/cooling_struct.h \
cooling/const_lambda/cooling.h cooling/const_lambda/cooling_struct.h \
......
src/potential.h
View file @ c0d32233
......@@ -34,8 +34,6 @@
#include "./potential/point_mass/potential.h"
#elif defined(EXTERNAL_POTENTIAL_ISOTHERMAL)
#include "./potential/isothermal/potential.h"
#elif defined(EXTERNAL_POTENTIAL_SOFTENED_ISOTHERMAL)
#include "./potential/softened_isothermal/potential.h"
#elif defined(EXTERNAL_POTENTIAL_DISC_PATCH)
#include "./potential/disc_patch/potential.h"
#else
......
src/potential/isothermal/potential.h
View file @ c0d32233
/*******************************************************************************
* This file is part of SWIFT.
* Copyright (c) 2016 Tom Theuns (tom.theuns@durham.ac.uk)
* Matthieu Schaller (matthieu.schaller@durham.ac.uk)
* Copyright (c) 2016 Tom Theuns (tom.theuns@durham.ac.uk)
* Stefan Arridge (stefan.arridge@durham.ac.uk)
* Matthieu Schaller (matthieu.schaller@durham.ac.uk)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
......@@ -35,7 +36,8 @@
#include "units.h"
/**
* @brief External Potential Properties - Isothermal sphere case
* @brief External Potential Properties - Isothermal sphere case with
* central softening
*/
struct external_potential {
......@@ -45,9 +47,14 @@ struct external_potential {
/*! Rotation velocity */
double vrot;
/*! Square of vrot divided by G \f$ \frac{v_{rot}^2}{G} \f$ */
/*! Square of vrot, the circular velocity which defines the isothermal
* potential devided by Newton's constant */
double vrot2_over_G;
/*! Square of the softening length. Acceleration tends to zero within this
* distance from the origin */
double epsilon2;
/*! Time-step condition pre-factor */
double timestep_mult;
};
......@@ -70,17 +77,18 @@ __attribute__((always_inline)) INLINE static float external_gravity_timestep(
const float dy = g->x[1] - potential->y;
const float dz = g->x[2] - potential->z;
const float rinv2 = 1.f / (dx * dx + dy * dy + dz * dz);
const float r2_plus_epsilon2_inv =
1.f / (dx * dx + dy * dy + dz * dz + potential->epsilon2);
const float drdv =
dx * (g->v_full[0]) + dy * (g->v_full[1]) + dz * (g->v_full[2]);
const double vrot = potential->vrot;
const float dota_x =
vrot * vrot * rinv2 * (g->v_full[0] - 2.f * drdv * dx * rinv2);
const float dota_y =
vrot * vrot * rinv2 * (g->v_full[1] - 2.f * drdv * dy * rinv2);
const float dota_z =
vrot * vrot * rinv2 * (g->v_full[2] - 2.f * drdv * dz * rinv2);
const float dota_x = vrot * vrot * r2_plus_epsilon2_inv *
(g->v_full[0] - 2.f * drdv * dx * r2_plus_epsilon2_inv);
const float dota_y = vrot * vrot * r2_plus_epsilon2_inv *
(g->v_full[1] - 2.f * drdv * dy * r2_plus_epsilon2_inv);
const float dota_z = vrot * vrot * r2_plus_epsilon2_inv *
(g->v_full[2] - 2.f * drdv * dz * r2_plus_epsilon2_inv);
const float dota_2 = dota_x * dota_x + dota_y * dota_y + dota_z * dota_z;
const float a_2 = g->a_grav[0] * g->a_grav[0] + g->a_grav[1] * g->a_grav[1] +
g->a_grav[2] * g->a_grav[2];
......@@ -94,6 +102,7 @@ __attribute__((always_inline)) INLINE static float external_gravity_timestep(
* Note that the accelerations are multiplied by Newton's G constant
* later on.
*
* a = v_rot^2 * (x,y,z) / (r^2 + epsilon^2)
* @param time The current time.
* @param potential The #external_potential used in the run.
* @param phys_const The physical constants in internal units.
......@@ -106,10 +115,10 @@ __attribute__((always_inline)) INLINE static void external_gravity_acceleration(
const float dx = g->x[0] - potential->x;
const float dy = g->x[1] - potential->y;
const float dz = g->x[2] - potential->z;
const float r2_plus_epsilon2_inv =
1.f / (dx * dx + dy * dy + dz * dz + potential->epsilon2);
const float rinv2 = 1.f / (dx * dx + dy * dy + dz * dz);
const double term = -potential->vrot2_over_G * rinv2;
const double term = -potential->vrot2_over_G * r2_plus_epsilon2_inv;
g->a_grav[0] += term * dx;
g->a_grav[1] += term * dy;
......@@ -134,9 +143,8 @@ external_gravity_get_potential_energy(
const float dz = g->x[2] - potential->z;
return 0.5f * potential->vrot * potential->vrot *
logf(dx * dx + dy * dy * dz * dz);
logf(dx * dx + dy * dy * dz * dz + potential->epsilon2);
}
/**
* @brief Initialises the external potential properties in the internal system
* of units.
......@@ -164,9 +172,11 @@ static INLINE void potential_init_backend(
parser_get_param_double(parameter_file, "IsothermalPotential:vrot");
potential->timestep_mult = parser_get_param_float(
parameter_file, "IsothermalPotential:timestep_mult");
const double epsilon =
parser_get_param_double(parameter_file, "IsothermalPotential:epsilon");
potential->vrot2_over_G =
potential->vrot * potential->vrot / phys_const->const_newton_G;
potential->epsilon2 = epsilon * epsilon;
}
/**
......@@ -180,9 +190,9 @@ static INLINE void potential_print_backend(
message(
"External potential is 'Isothermal' with properties are (x,y,z) = (%e, "
"%e, %e), vrot = %e "
"timestep multiplier = %e.",
"timestep multiplier = %e, epsilon = %e",
potential->x, potential->y, potential->z, potential->vrot,
potential->timestep_mult);
potential->timestep_mult, sqrtf(potential->epsilon2));
}
#endif /* SWIFT_POTENTIAL_ISOTHERMAL_H */
#endif /* SWIFT_ISOTHERMAL_H */
src/potential/softened_isothermal/potential.h deleted 100644 → 0
View file @ e8c2ac7a
/*******************************************************************************
* This file is part of SWIFT.
* Copyright (c) 2016 Stefan Arridge (stefan.arridge@durham.ac.uk)
* Matthieu Schaller (matthieu.schaller@durham.ac.uk)
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
******************************************************************************/
#ifndef SWIFT_POTENTIAL_SOFTENED_ISOTHERMAL_H
#define SWIFT_POTENTIAL_SOFTENED_ISOTHERMAL_H
/* Config parameters. */
#include "../config.h"
/* Some standard headers. */
#include <math.h>
/* Local includes. */
#include "error.h"
#include "parser.h"
#include "part.h"
#include "physical_constants.h"
#include "space.h"
#include "units.h"
/**
* @brief External Potential Properties - Softened Isothermal sphere case
*/
struct external_potential {
/*! Position of the centre of potential */
double x, y, z;
/*! Rotation velocity */
double vrot;
/*! Square of vrot, the circular velocity which defines the isothermal
* potential */
double vrot2_over_G;
/*! Square of the softening length. Acceleration tends to zero within this
* distance from the origin */
double epsilon2;
/*! Time-step condition pre-factor */
double timestep_mult;
};
/**
* @brief Computes the time-step due to the acceleration from an isothermal
* potential.
*
* @param time The current time.
* @param potential The #external_potential used in the run.
* @param phys_const The physical constants in internal units.
* @param g Pointer to the g-particle data.
*/
__attribute__((always_inline)) INLINE static float external_gravity_timestep(
double time, const struct external_potential* restrict potential,
const struct phys_const* restrict phys_const,
const struct gpart* restrict g) {
const float dx = g->x[0] - potential->x;
const float dy = g->x[1] - potential->y;
const float dz = g->x[2] - potential->z;
const float r2_plus_epsilon2_inv =
1.f / (dx * dx + dy * dy + dz * dz + potential->epsilon2);
const float drdv =
dx * (g->v_full[0]) + dy * (g->v_full[1]) + dz * (g->v_full[2]);
const double vrot = potential->vrot;
const float dota_x = vrot * vrot * r2_plus_epsilon2_inv *
(g->v_full[0] - 2.f * drdv * dx * r2_plus_epsilon2_inv);
const float dota_y = vrot * vrot * r2_plus_epsilon2_inv *
(g->v_full[1] - 2.f * drdv * dy * r2_plus_epsilon2_inv);
const float dota_z = vrot * vrot * r2_plus_epsilon2_inv *
(g->v_full[2] - 2.f * drdv * dz * r2_plus_epsilon2_inv);
const float dota_2 = dota_x * dota_x + dota_y * dota_y + dota_z * dota_z;
const float a_2 = g->a_grav[0] * g->a_grav[0] + g->a_grav[1] * g->a_grav[1] +
g->a_grav[2] * g->a_grav[2];
return potential->timestep_mult * sqrtf(a_2 / dota_2);
}
/**
* @brief Computes the gravitational acceleration from an isothermal potential.
*
* Note that the accelerations are multiplied by Newton's G constant
* later on.
*
* a = v_rot^2 * (x,y,z) / (r^2 + epsilon^2)
* @param time The current time.
* @param potential The #external_potential used in the run.
* @param phys_const The physical constants in internal units.
* @param g Pointer to the g-particle data.
*/
__attribute__((always_inline)) INLINE static void external_gravity_acceleration(
double time, const struct external_potential* potential,
const struct phys_const* const phys_const, struct gpart* g) {
const float dx = g->x[0] - potential->x;
const float dy = g->x[1] - potential->y;
const float dz = g->x[2] - potential->z;
const float r2_plus_epsilon2_inv =
1.f / (dx * dx + dy * dy + dz * dz + potential->epsilon2);
const double term = -potential->vrot2_over_G * r2_plus_epsilon2_inv;
g->a_grav[0] += term * dx;
g->a_grav[1] += term * dy;
g->a_grav[2] += term * dz;
}
/**
* @brief Computes the gravitational potential energy of a particle in an
* isothermal potential.
*
* @param potential The #external_potential used in the run.
* @param phys_const Physical constants in internal units.
* @param g Pointer to the particle data.
*/
__attribute__((always_inline)) INLINE static float
external_gravity_get_potential_energy(
const struct external_potential* potential,
const struct phys_const* const phys_const, const struct gpart* g) {
const float dx = g->x[0] - potential->x;
const float dy = g->x[1] - potential->y;
const float dz = g->x[2] - potential->z;
return 0.5f * potential->vrot * potential->vrot *
logf(dx * dx + dy * dy * dz * dz + potential->epsilon2);
}
/**
* @brief Initialises the external potential properties in the internal system
* of units.
*
* @param parameter_file The parsed parameter file
* @param phys_const Physical constants in internal units
* @param us The current internal system of units
* @param potential The external potential properties to initialize
*/
static INLINE void potential_init_backend(
const struct swift_params* parameter_file,
const struct phys_const* phys_const, const struct UnitSystem* us,
const struct space* s, struct external_potential* potential) {
potential->x = s->dim[0] / 2. +
parser_get_param_double(
parameter_file, "SoftenedIsothermalPotential:position_x");
potential->y = s->dim[1] / 2. +
parser_get_param_double(
parameter_file, "SoftenedIsothermalPotential:position_y");
potential->z = s->dim[2] / 2. +
parser_get_param_double(
parameter_file, "SoftenedIsothermalPotential:position_z");
potential->vrot = parser_get_param_double(parameter_file,
"SoftenedIsothermalPotential:vrot");
potential->timestep_mult = parser_get_param_float(
parameter_file, "SoftenedIsothermalPotential:timestep_mult");
const double epsilon = parser_get_param_float(
parameter_file, "SoftenedIsothermalPotential:epsilon");
potential->vrot2_over_G =
potential->vrot * potential->vrot / phys_const->const_newton_G;
potential->epsilon2 = epsilon * epsilon;
}
/**
* @brief Prints the properties of the external potential to stdout.
*
* @param potential The external potential properties.
*/
static INLINE void potential_print_backend(
const struct external_potential* potential) {
message(
"External potential is 'Isothermal' with properties are (x,y,z) = (%e, "
"%e, %e), vrot = %e "
"timestep multiplier = %e, epsilon = %e",
potential->x, potential->y, potential->z, potential->vrot,
potential->timestep_mult, sqrtf(potential->epsilon2));
}
#endif /* SWIFT_POTENTIAL_ISOTHERMAL_H */
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