IMP
2.2.1
The Integrative Modeling Platform
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Simple Brownian dynamics simulator. More...
#include <IMP/atom/BrownianDynamics.h>
Public Member Functions | |
BrownianDynamics (kernel::Model *m, std::string name="BrownianDynamics%1%", double wave_factor=1.0) | |
Create the optimizer. More... | |
virtual std::string | get_type_name () const |
virtual ::IMP::base::VersionInfo | get_version_info () const |
Get information about the module and version of the object. | |
void | set_maximum_move (double ms) |
void | set_use_stochastic_runge_kutta (bool tf) |
Public Member Functions inherited from IMP::atom::Simulator | |
Simulator (kernel::Model *m, std::string name="Simulator %1%", double wave_factor=1.0) | |
double | get_current_time () const |
double | get_kt () const |
kernel::ParticleIndexes | get_simulation_particle_indexes () const |
kernel::ParticlesTemp | get_simulation_particles () const |
double | get_temperature () const |
void | set_current_time (double ct) |
void | set_temperature (double d) |
double | simulate (double time_in_fs) |
Simulate for a given time in fs. More... | |
double | simulate_wave (double time_in_fs, double max_time_step_factor=10.0, double base=1.5) |
void | set_maximum_time_step (double ts) |
double | get_maximum_time_step () const |
double | get_last_time_step () const |
void | remove_particle (kernel::Particle *d) |
void | remove_particles (const kernel::Particles &d) |
void | set_particles (const kernel::Particles &ps) |
void | set_particles_order (const kernel::Particles &objs) |
unsigned int | add_particle (kernel::Particle *obj) |
void | add_particles (const kernel::Particles &objs) |
void | clear_particles () |
unsigned int | get_number_of_particles () const |
bool | get_has_particles () |
kernel::Particle * | get_particle (unsigned int i) const |
kernel::Particles | get_particles () const |
void | reserve_particles (unsigned int sz) |
Public Member Functions inherited from IMP::kernel::Optimizer | |
Optimizer (kernel::Model *m, std::string name="Optimizer %1%") | |
double | get_last_score () const |
Return the score found in the last evaluate. | |
ScoringFunction * | get_scoring_function () const |
Return the scoring function that is being used. | |
bool | get_stop_on_good_score () const |
double | optimize (unsigned int max_steps) |
Optimize the model for up to max_steps iterations. More... | |
virtual void | set_scoring_function (ScoringFunctionAdaptor sf) |
void | set_stop_on_good_score (bool tf) |
void | remove_optimizer_state (OptimizerState *d) |
void | remove_optimizer_states (const OptimizerStates &d) |
void | set_optimizer_states (const OptimizerStates &ps) |
void | set_optimizer_states_order (const OptimizerStates &objs) |
unsigned int | add_optimizer_state (OptimizerState *obj) |
void | add_optimizer_states (const OptimizerStates &objs) |
void | clear_optimizer_states () |
unsigned int | get_number_of_optimizer_states () const |
bool | get_has_optimizer_states () |
OptimizerState * | get_optimizer_state (unsigned int i) const |
OptimizerStates | get_optimizer_states () const |
void | reserve_optimizer_states (unsigned int sz) |
Public Member Functions inherited from IMP::kernel::ModelObject | |
ModelObject (kernel::Model *m, std::string name) | |
bool | get_has_dependencies () const |
Return whether this object has dependencies computed. | |
bool | get_has_required_score_states () const |
ModelObjectsTemp | get_inputs () const |
ModelObjectsTemps | get_interactions () const |
Model * | get_model () const |
ModelObjectsTemp | get_outputs () const |
const ScoreStatesTemp & | get_required_score_states () const |
void | set_has_dependencies (bool tf) |
void | set_has_required_score_states (bool tf) |
Public Member Functions inherited from IMP::base::Object | |
virtual void | clear_caches () |
virtual void | do_destroy () |
CheckLevel | get_check_level () const |
LogLevel | get_log_level () const |
void | set_check_level (CheckLevel l) |
void | set_log_level (LogLevel l) |
Set the logging level used in this object. More... | |
void | set_was_used (bool tf) const |
void | show (std::ostream &out=std::cout) const |
const std::string & | get_name () const |
void | set_name (std::string name) |
Additional Inherited Members | |
Protected Member Functions inherited from IMP::atom::Simulator | |
virtual Float | do_optimize (unsigned int max_steps) |
override this function to do actual optimization | |
Protected Member Functions inherited from IMP::kernel::Optimizer | |
virtual ModelObjectsTemp | do_get_inputs () const |
virtual ModelObjectsTemp | do_get_outputs () const |
don't return anything here to avoid pointless dependencies | |
ModelObjectsTemp | get_optimizer_state_inputs () const |
void | update_states () const |
Update optimizer states, should be called at each successful step. More... | |
Protected Member Functions inherited from IMP::kernel::ModelObject | |
virtual ModelObjectsTemps | do_get_interactions () const |
virtual void | handle_set_has_required_score_states (bool) |
Protected Member Functions inherited from IMP::base::Object | |
Object (std::string name) | |
Construct an object with the given name. More... | |
This is an implementation of a Brownian Dynamics simulator.
Input particles and score
Each optimized particle must have x,y,z attributes that are optimizable. In addition, each optimized particle must be decorated with the Diffusion decorator. Optionally, the RigidBodyDiffusion decorator can be used to specify a rotational diffusion coefficient for core::RigidBody particles. The optimizer assumes the scoring function to be energy in kcal/mol, and the xyz coordinates to be in angstroms and the diffusion coefficent of each particle be in \(A^2/fs\) (or \(Radian^2/fs\) for rotational diffusion coefficient). kernel::Particles without optimized x,y,z and nonoptimized D are skipped.
The optimizer can either automatically determine which particles to use from the model or be passed a SingletonContainer for the particles. If such a container is passed, particles added to it during optimization state updates are handled properly.
Simulation
At each simulation time step, each particle is translated in the direction of the sum of a random diffusion vector and the gradient of the scoring function (force field) at the particle coordinates. The translation is proportional to the particle diffusion coefficient, the time step size, and the inverse of kT. Note that particles masses are not considered, only their diffusion coefficients.
Similarly, rigid bodies are rotated by the sum of a random torque and a force field torque, proportionally to the rotational diffusion coefficient, the time step size, and inversely proportional kT.
If the skt (stochastic runge kutta) flag is true, the simulation is altered slightly to apply the SKT scheme.
Definition at line 67 of file BrownianDynamics.h.
IMP::atom::BrownianDynamics::BrownianDynamics | ( | kernel::Model * | m, |
std::string | name = "BrownianDynamics%1%" , |
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double | wave_factor = 1.0 |
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If sc is not null, that container will be used to find particles to move, otherwise the model will be searched.
m | model associated with bd |
name | name of bd object |
wave_factor | for wave step function, see Simulator object, if >1.001 or so, creates a wave of time steps that are larger by up to wave_factor from formal maximal time step |