SimTK::GeneralForceSubsystem Class Reference

This is a concrete subsystem which can apply arbitrary forces to a MultibodySystem. More...

#include <GeneralForceSubsystem.h>

Inheritance diagram for SimTK::GeneralForceSubsystem:

List of all members.

Public Member Functions
	GeneralForceSubsystem ()
	GeneralForceSubsystem (MultibodySystem &)
ForceIndex	adoptForce (Force &force)
	Attach a new force to this subsystem.
int	getNumForces () const
	Get the number of force elements which have been added to this Subsystem.
const Force &	getForce (ForceIndex index) const
	Get a const reference to a force element by index.
Force &	updForce (ForceIndex index)
	Get a writable reference to a force element by index.
bool	isForceDisabled (const State &state, ForceIndex index) const
	Find out whether a particular force element contained in this subsystem is currently disabled in the given state.
void	setForceIsDisabled (State &state, ForceIndex index, bool shouldBeDisabled) const
	Disable or enable a particular force element contained in this subsystem.
const MultibodySystem &	getMultibodySystem () const
	Every Subsystem is owned by a System; a GeneralForceSubsystem expects to be owned by a MultibodySystem.

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Detailed Description

This is a concrete subsystem which can apply arbitrary forces to a MultibodySystem.

Each force element is represented by a Force object. For example, to add a spring between two bodies, you would write

    GeneralForceSubsystem forces(system);
    // ...
    Force::TwoPointLinearSpring(forces, body1, station1, body2, station2, k, x0);

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Constructor & Destructor Documentation

SimTK::GeneralForceSubsystem::GeneralForceSubsystem

(

)

SimTK::GeneralForceSubsystem::GeneralForceSubsystem

(

MultibodySystem &

)

[explicit]

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Member Function Documentation

ForceIndex SimTK::GeneralForceSubsystem::adoptForce

(

Force &

force

)

Attach a new force to this subsystem.

The subsystem takes over ownership of the force, leaving the passed in handle as a reference to it. This is normally called by the Force handle constructor.

Parameters:

force

A writable reference to a Force handle whose referenced force element is not yet owned by any subsystem. We will take over ownership of the ForceImpl implementation objected referenced by the handle, bumping the reference count and leaving the reference in place so that the original handle can continue to be used to reference and modify the force element.

Returns:

A unique integer index for the adopted force element that can be used to retrieve this force element from the subsystem later if needed.

int SimTK::GeneralForceSubsystem::getNumForces

(

)

const

Get the number of force elements which have been added to this Subsystem.

Legal ForceIndex values range from 0 to getNumForces()-1.

const Force& SimTK::GeneralForceSubsystem::getForce

(

ForceIndex

index

)

const

Get a const reference to a force element by index.

Force& SimTK::GeneralForceSubsystem::updForce

(

ForceIndex

index

)

Get a writable reference to a force element by index.

bool SimTK::GeneralForceSubsystem::isForceDisabled	(	const State &	state,
		ForceIndex	index
	)		const

Find out whether a particular force element contained in this subsystem is currently disabled in the given state.

void SimTK::GeneralForceSubsystem::setForceIsDisabled	(	State &	state,
		ForceIndex	index,
		bool	shouldBeDisabled
	)		const

Disable or enable a particular force element contained in this subsystem.

This can usually be done more conveniently through the Force handle's disable() and enable() methods. Note that although force elements are normally enabled when created, it is possible that the force element will have been constructed to be disabled by default in which case it must be explicitly enabled.

const MultibodySystem& SimTK::GeneralForceSubsystem::getMultibodySystem

(

)

const

Every Subsystem is owned by a System; a GeneralForceSubsystem expects to be owned by a MultibodySystem.

This method returns a const reference to the containing MultibodySystem and will throw an exception if there is no containing System or it is not a MultibodySystem.

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The documentation for this class was generated from the following file:

• GeneralForceSubsystem.h