SOFA API  384d495c
Open source framework for multi-physics simuation
sofa::component::odesolver::forward::EulerExplicitSolver Class Reference

#include <EulerSolver.h>

Inheritance diagram for sofa::component::odesolver::forward::EulerExplicitSolver:

Detailed Description

The simplest time integration. Two variants of the Euler solver are available in this component:

  • forward Euler method, also called explicit Euler method
  • semi-implicit Euler method, also called semi-explicit Euler method or symplectic Euler

In both variants, acceleration is first computed. The system to compute the acceleration is M * a = f, where M is the mass matrix and f can be a force. In case of a diagonal mass matrix, M is trivially invertible and the acceleration can be computed without a linear solver.

f is accumulated by force fields through the addForce function. Mappings can also contribute by projecting forces of mapped objects. f is computed based on the current state (current velocity and position).

Explicit Euler method: The option "symplectic" must be set to false to use this variant. The explicit Euler method produces an approximate discrete solution by iterating x_{n+1} = x_n + v_n * dt v_{n+1} = v_n + a * dt

Semi-implicit Euler method: The option "symplectic" must be set to true to use this variant. The semi-implicit Euler method produces an approximate discrete solution by iterating v_{n+1} = v_n + a * dt x_{n+1} = x_n + v_{n+1} * dt

The semi-implicit Euler method is more robust than the standard Euler method.

Public Attributes

Data< bool > d_symplectic
 If true, the velocities are updated before the positions and the method is symplectic (more robust). If false, the positions are updated before the velocities (standard Euler, less robust). More...
 
Data< bool > d_threadSafeVisitor
 If true, do not use realloc and free visitors in fwdInteractionForceField. More...
 
- Public Attributes inherited from sofa::core::objectmodel::BaseObject
Data< bool > f_listening
 if true, handle the events, otherwise ignore the events More...
 
- Public Attributes inherited from sofa::core::objectmodel::Base
std::vector< lifecycle::DeprecatedData * > m_oldAttributes
 
Data< intd_messageLogCount
 
Data< std::string > name
 Name of the object. More...
 
Data< bool > f_printLog
 if true, emits extra messages at runtime. More...
 
Data< sofa::core::objectmodel::TagSetf_tags
 list of the subsets the objet belongs to More...
 
Data< sofa::type::BoundingBoxf_bbox
 this object bounding box More...
 
Data< sofa::core::objectmodel::ComponentStated_componentState
 the object state More...
 
std::string m_definitionSourceFileName {""}
 
int m_definitionSourceFilePos {-1}
 
std::string m_instanciationSourceFileName {""}
 
int m_instanciationSourceFilePos {-1}
 

Public Member Functions

 SOFA_CLASS (EulerExplicitSolver, sofa::core::behavior::OdeSolver)
 
void solve (const core::ExecParams *params, SReal dt, sofa::core::MultiVecCoordId xResult, sofa::core::MultiVecDerivId vResult) override
 
SReal getIntegrationFactor (int inputDerivative, int outputDerivative) const override
 
SReal getSolutionIntegrationFactor (int outputDerivative) const override
 
void init () override
 Initialization method called at graph creation and modification, during top-down traversal. More...
 
void parse (sofa::core::objectmodel::BaseObjectDescription *arg) override
 Parse the given description to assign values to this object's fields and potentially other parameters. More...
 
- Public Member Functions inherited from sofa::core::behavior::OdeSolver
 SOFA_ABSTRACT_CLASS (OdeSolver, objectmodel::BaseObject)
 
virtual void solve (const core::ExecParams *params, SReal dt)
 
virtual void computeResidual (const core::ExecParams *, SReal, sofa::core::MultiVecCoordId, sofa::core::MultiVecDerivId)
 
virtual SReal getVelocityIntegrationFactor () const
 
virtual SReal getPositionIntegrationFactor () const
 
bool insertInNode (objectmodel::BaseNode *node) override
 
bool removeInNode (objectmodel::BaseNode *node) override
 
- Public Member Functions inherited from sofa::core::objectmodel::BaseObject
 SOFA_CLASS (BaseObject, Base)
 
virtual void draw (const core::visual::VisualParams *)
 Render internal data of this object, for debugging purposes. More...
 
virtual void computeBBox (const core::ExecParams *, bool=false)
 
void setSrc (const std::string &v, std::vector< std::string > *attributeList=nullptr)
 Sets a source Object and parses it to collect dependent Data. More...
 
void setSrc (const std::string &v, const BaseObject *loader, std::vector< std::string > *attributeList=nullptr)
 
BasefindLinkDestClass (const BaseClass *destType, const std::string &path, const BaseLink *link) override
 
virtual std::string getPathName () const override
 Return the full path name of this object. More...
 
SReal getTime () const
 Current time. More...
 
const BaseContextgetContext () const
 
BaseContextgetContext ()
 
const BaseObjectgetMaster () const
 
BaseObjectgetMaster ()
 
const VecSlavesgetSlaves () const
 
BaseObjectgetSlave (const std::string &name) const
 
virtual void addSlave (BaseObject::SPtr s)
 
virtual void removeSlave (BaseObject::SPtr s)
 
virtual void handleEvent (Event *)
 Handle an event. More...
 
virtual void handleTopologyChange ()
 
virtual void handleTopologyChange (core::topology::Topology *t)
 
void parse (BaseObjectDescription *arg) override
 Parse the given description to assign values to this object's fields and potentially other parameters. More...
 
virtual void bwdInit ()
 Initialization method called at graph creation and modification, during bottom-up traversal. More...
 
virtual void reinit ()
 Update method called when variables used in precomputation are modified. More...
 
void updateInternal ()
 Update method called when variables (used to compute other internal variables) are modified. More...
 
virtual void storeResetState ()
 Save the initial state for later uses in reset() More...
 
virtual void reset ()
 Reset to initial state. More...
 
virtual void cleanup ()
 
- Public Member Functions inherited from sofa::core::objectmodel::Base
virtual const BaseClassgetClass () const
 
void addDeprecatedAttribute (lifecycle::DeprecatedData *attribute)
 
void addUpdateCallback (const std::string &name, std::initializer_list< BaseData * > inputs, std::function< sofa::core::objectmodel::ComponentState(const DataTracker &)> function, std::initializer_list< BaseData * > outputs)
 
void addOutputsToCallback (const std::string &name, std::initializer_list< BaseData * > outputs)
 
const std::string & getName () const
 Accessor to the object name. More...
 
void setName (const std::string &n)
 Set the name of this object. More...
 
void setName (const std::string &n, int counter)
 Set the name of this object, adding an integer counter. More...
 
std::string getTypeName () const
 Get the type name of this object (i.e. class and template types) More...
 
virtual std::string getClassName () const
 Get the class name of this object. More...
 
virtual std::string getTemplateName () const final
 Get the template type names (if any) used to instantiate this object. More...
 
std::string getNameSpaceName () const
 Get the template type names (if any) used to instantiate this object. More...
 
void setDefinitionSourceFileName (const std::string &sourceFileName)
 Set the source filename (where the component is implemented) More...
 
const std::string & getDefinitionSourceFileName () const
 Get the source filename (where the component is implemented) More...
 
void setDefinitionSourceFilePos (const int)
 Set the source location (where the component is implemented) More...
 
int getDefinitionSourceFilePos () const
 Get the source location (where the component is implemented) More...
 
void setInstanciationSourceFileName (const std::string &sourceFileName)
 
const std::string & getInstanciationSourceFileName () const
 
void setInstanciationSourceFilePos (const int)
 
int getInstanciationSourceFilePos () const
 
void addMessage (const sofa::helper::logging::Message &m) const
 
size_t countLoggedMessages (sofa::helper::logging::Message::TypeSet t=sofa::helper::logging::Message::AnyTypes) const
 
const std::deque< sofa::helper::logging::Message > & getLoggedMessages () const
 
const std::string getLoggedMessagesAsString (sofa::helper::logging::Message::TypeSet t=sofa::helper::logging::Message::AnyTypes) const
 
void clearLoggedMessages () const
 
bool notMuted () const
 
const sofa::core::objectmodel::TagSetgetTags () const
 Represents the subsets the object belongs to. More...
 
bool hasTag (Tag t) const
 Return true if the object belong to the given subset. More...
 
void addTag (Tag t)
 Add a subset qualification to the object. More...
 
void removeTag (Tag t)
 Remove a subset qualification to the object. More...
 
ComponentState getComponentState () const
 
bool isComponentStateValid () const
 
virtual bool parseField (const std::string &attribute, const std::string &value)
 Assign one field value (Data or Link) More...
 
virtual bool hasField (const std::string &attribute) const
 Check if a given Data field or Link exists. More...
 
void parseFields (const std::list< std::string > &str)
 Assign the field values stored in the given list of name + value pairs of strings. More...
 
virtual void parseFields (const std::map< std::string, std::string * > &str)
 Assign the field values stored in the given map of name -> value pairs. More...
 
void writeDatas (std::map< std::string, std::string * > &str)
 Write the current field values to the given map of name -> value pairs. More...
 
void writeDatas (std::ostream &out, const std::string &separator=" ")
 
BaseDatafindData (const std::string &name) const
 
std::vector< BaseData * > findGlobalField (const std::string &name) const
 Find data fields given a name: several can be found as we look into the alias map. More...
 
BaseLinkfindLink (const std::string &name) const
 
std::vector< BaseLink * > findLinks (const std::string &name) const
 Find link fields given a name: several can be found as we look into the alias map. More...
 
virtual void updateLinks (bool logErrors=true)
 Update pointers in case the pointed-to objects have appeared. More...
 
template<class T >
BaseData::BaseInitData initData (::sofa::core::objectmodel::Data< T > *field, const char *name, const char *help, ::sofa::core::objectmodel::BaseData::DataFlags dataflags)
 Helper method used to initialize a data field containing a value of type T. More...
 
template<class T >
BaseData::BaseInitData initData (Data< T > *field, const char *name, const char *help, bool isDisplayed=true, bool isReadOnly=false)
 Helper method used to initialize a data field containing a value of type T. More...
 
template<class T >
Data< T >::InitData initData (Data< T > *field, const T &value, const char *name, const char *help, bool isDisplayed=true, bool isReadOnly=false)
 Helper method used to initialize a data field containing a value of type T. More...
 
void addData (BaseData *f, const std::string &name)
 
void addData (BaseData *f)
 
void removeData (BaseData *f)
 Remove a data field. More...
 
void addAlias (BaseData *field, const char *alias)
 Add an alias to a Data. More...
 
void addLink (BaseLink *l)
 Add a link. More...
 
void addAlias (BaseLink *link, const char *alias)
 Add an alias to a Link. More...
 
const VecDatagetDataFields () const
 Accessor to the vector containing all the fields of this object. More...
 
const MapDatagetDataAliases () const
 Accessor to the map containing all the aliases of this object. More...
 
const VecLinkgetLinks () const
 Accessor to the vector containing all the fields of this object. More...
 
const MapLinkgetLinkAliases () const
 Accessor to the map containing all the aliases of this object. More...
 
virtual bool findDataLinkDest (BaseData *&ptr, const std::string &path, const BaseLink *link)
 
template<class T >
bool findLinkDest (T *&ptr, const std::string &path, const BaseLink *link)
 

Protected Member Functions

 EulerExplicitSolver ()
 
void updateState (sofa::simulation::common::VectorOperations *vop, sofa::simulation::common::MechanicalOperations *mop, sofa::core::MultiVecCoordId xResult, sofa::core::MultiVecDerivId vResult, const sofa::core::behavior::MultiVecDeriv &acc, SReal dt) const
 
- Protected Member Functions inherited from sofa::core::behavior::OdeSolver
 OdeSolver ()
 
 ~OdeSolver () override
 
- Protected Member Functions inherited from sofa::core::objectmodel::BaseObject
 BaseObject ()
 
 ~BaseObject () override
 
virtual void doUpdateInternal ()
 Implementation of the internal update. More...
 
void changeContextLink (BaseContext *before, BaseContext *&after)
 
void changeSlavesLink (BaseObject::SPtr ptr, std::size_t, bool add)
 This method insures that slaves objects have master and context links set correctly. More...
 
void trackInternalData (const BaseData &data)
 Method called to add the Data to the DataTracker (listing the Data to track) More...
 
void cleanTracker ()
 
bool hasDataChanged (const BaseData &data)
 Method called to know if a tracked Data has changed. More...
 
- Protected Member Functions inherited from sofa::core::objectmodel::Base
 Base ()
 
virtual ~Base ()
 
void initData0 (BaseData *field, BaseData::BaseInitData &res, const char *name, const char *help, bool isDisplayed=true, bool isReadOnly=false)
 Helper method used by initData() More...
 
void initData0 (BaseData *field, BaseData::BaseInitData &res, const char *name, const char *help, BaseData::DataFlags dataFlags)
 Helper method used by initData() More...
 
template<class T >
void initData0 (Data< T > *field, typename Data< T >::InitData &res, const T &value, const char *name, const char *help, bool isDisplayed=true, bool isReadOnly=false)
 Helper method used by initData() More...
 

Static Protected Member Functions

static void addSeparateGravity (sofa::simulation::common::MechanicalOperations *mop, SReal dt, core::MultiVecDerivId v)
 
static void computeForce (sofa::simulation::common::MechanicalOperations *mop, core::MultiVecDerivId f)
 Assemble the force vector (right-hand side of the equation) More...
 
static void computeAcceleration (sofa::simulation::common::MechanicalOperations *mop, core::MultiVecDerivId acc, core::ConstMultiVecDerivId f)
 
static void projectResponse (sofa::simulation::common::MechanicalOperations *mop, core::MultiVecDerivId vecId)
 Apply projective constraints, such as FixedConstraint. More...
 
static void solveConstraints (sofa::simulation::common::MechanicalOperations *mop, core::MultiVecDerivId acc)
 
static void assembleSystemMatrix (core::behavior::MultiMatrix< simulation::common::MechanicalOperations > *matrix)
 
static void solveSystem (core::behavior::MultiMatrix< simulation::common::MechanicalOperations > *matrix, core::MultiVecDerivId solution, core::MultiVecDerivId rhs)
 

Additional Inherited Members

- Protected Attributes inherited from sofa::core::objectmodel::BaseObject
SingleLink< BaseObject, BaseContext, BaseLink::FLAG_DOUBLELINKl_context
 
LinkSlaves l_slaves
 
SingleLink< BaseObject, BaseObject, BaseLink::FLAG_DOUBLELINKl_master
 
- Protected Attributes inherited from sofa::core::objectmodel::Base
std::map< std::string, sofa::core::DataTrackerCallbackm_internalEngine
 
VecData m_vecData
 List of fields (Data instances) More...
 
MapData m_aliasData
 name -> Data multi-map (includes names and aliases) More...
 
VecLink m_vecLink
 List of links. More...
 
MapLink m_aliasLink
 name -> Link multi-map (includes names and aliases) More...
 
- Static Public Member Functions inherited from sofa::core::objectmodel::BaseObject
template<class T >
static bool canCreate (T *, BaseContext *, BaseObjectDescription *)
 Pre-construction check method called by ObjectFactory. More...
 
template<class T >
static T::SPtr create (T *, BaseContext *context, BaseObjectDescription *arg)
 Construction method called by ObjectFactory. More...
 
- Static Public Member Functions inherited from sofa::core::objectmodel::Base
static const BaseClassGetClass ()
 
template<class T >
static std::string shortName (const T *ptr=nullptr, BaseObjectDescription *=nullptr)
 

Attribute details

◆ d_symplectic

Data<bool> sofa::component::odesolver::forward::EulerExplicitSolver::d_symplectic

If true, the velocities are updated before the positions and the method is symplectic (more robust). If false, the positions are updated before the velocities (standard Euler, less robust).

◆ d_threadSafeVisitor

Data<bool> sofa::component::odesolver::forward::EulerExplicitSolver::d_threadSafeVisitor

If true, do not use realloc and free visitors in fwdInteractionForceField.

Constructor details

◆ EulerExplicitSolver()

sofa::component::odesolver::forward::EulerExplicitSolver::EulerExplicitSolver ( )
protected

Function details

◆ addSeparateGravity()

void sofa::component::odesolver::forward::EulerExplicitSolver::addSeparateGravity ( sofa::simulation::common::MechanicalOperations mop,
SReal  dt,
core::MultiVecDerivId  v 
)
staticprotected

Gravity times time step size is added to the velocity for some masses v += g * dt

◆ assembleSystemMatrix()

void sofa::component::odesolver::forward::EulerExplicitSolver::assembleSystemMatrix ( core::behavior::MultiMatrix< simulation::common::MechanicalOperations > *  matrix)
staticprotected

◆ computeAcceleration()

void sofa::component::odesolver::forward::EulerExplicitSolver::computeAcceleration ( sofa::simulation::common::MechanicalOperations mop,
core::MultiVecDerivId  acc,
core::ConstMultiVecDerivId  f 
)
staticprotected

Compute the acceleration from the force and the inverse of the mass acc = M^-1 * f

◆ computeForce()

void sofa::component::odesolver::forward::EulerExplicitSolver::computeForce ( sofa::simulation::common::MechanicalOperations mop,
core::MultiVecDerivId  f 
)
staticprotected

Assemble the force vector (right-hand side of the equation)

◆ getIntegrationFactor()

SReal sofa::component::odesolver::forward::EulerExplicitSolver::getIntegrationFactor ( int  inputDerivative,
int  outputDerivative 
) const
overridevirtual

Given an input derivative order (0 for position, 1 for velocity, 2 for acceleration), how much will it affect the output derivative of the given order.

Reimplemented from sofa::core::behavior::OdeSolver.

◆ getSolutionIntegrationFactor()

SReal sofa::component::odesolver::forward::EulerExplicitSolver::getSolutionIntegrationFactor ( int  outputDerivative) const
overridevirtual

Given a solution of the linear system, how much will it affect the output derivative of the given order.

Reimplemented from sofa::core::behavior::OdeSolver.

◆ init()

void sofa::component::odesolver::forward::EulerExplicitSolver::init ( )
overridevirtual

Initialization method called at graph creation and modification, during top-down traversal.

Reimplemented from sofa::core::objectmodel::BaseObject.

◆ parse()

void sofa::component::odesolver::forward::EulerExplicitSolver::parse ( sofa::core::objectmodel::BaseObjectDescription arg)
overridevirtual

Parse the given description to assign values to this object's fields and potentially other parameters.

Reimplemented from sofa::core::objectmodel::Base.

◆ projectResponse()

void sofa::component::odesolver::forward::EulerExplicitSolver::projectResponse ( sofa::simulation::common::MechanicalOperations mop,
core::MultiVecDerivId  vecId 
)
staticprotected

Apply projective constraints, such as FixedConstraint.

◆ SOFA_CLASS()

sofa::component::odesolver::forward::EulerExplicitSolver::SOFA_CLASS ( EulerExplicitSolver  ,
sofa::core::behavior::OdeSolver   
)

◆ solve()

void sofa::component::odesolver::forward::EulerExplicitSolver::solve ( const core::ExecParams ,
SReal  ,
sofa::core::MultiVecCoordId  ,
sofa::core::MultiVecDerivId   
)
overridevirtual

Main computation method.

Specify and execute all computation for timestep integration, i.e. advancing the state from time t to t+dt, putting the resulting position and velocity in the provided vectors.

Implements sofa::core::behavior::OdeSolver.

◆ solveConstraints()

void sofa::component::odesolver::forward::EulerExplicitSolver::solveConstraints ( sofa::simulation::common::MechanicalOperations mop,
core::MultiVecDerivId  acc 
)
staticprotected

◆ solveSystem()

void sofa::component::odesolver::forward::EulerExplicitSolver::solveSystem ( core::behavior::MultiMatrix< simulation::common::MechanicalOperations > *  matrix,
core::MultiVecDerivId  solution,
core::MultiVecDerivId  rhs 
)
staticprotected

◆ updateState()

void sofa::component::odesolver::forward::EulerExplicitSolver::updateState ( sofa::simulation::common::VectorOperations vop,
sofa::simulation::common::MechanicalOperations mop,
sofa::core::MultiVecCoordId  xResult,
sofa::core::MultiVecDerivId  vResult,
const sofa::core::behavior::MultiVecDeriv acc,
SReal  dt 
) const
protected

Update state variable (new position and velocity) based on the computed acceleration The update takes constraints into account