This class serves as a serializable ForceVelocityCurve for use in muscle models. More...

Inheritance diagram for OpenSim::ForceVelocityCurve:

OpenSim Properties, Sockets, Outputs, Inputs
Properties (single-value)
double	concentric_slope_at_vmax
	"Curve slope at the maximum normalized concentric (shortening) velocity (normalized velocity of -1)" More...

double	concentric_slope_near_vmax
	"Curve slope just before reaching concentric_slope_at_vmax" More...

double	isometric_slope
	"Curve slope at isometric (normalized velocity of 0)" More...

double	eccentric_slope_at_vmax
	"Curve slope at the maximum normalized eccentric (lengthening) velocity (normalized velocity of 1)" More...

double	eccentric_slope_near_vmax
	"Curve slope just before reaching eccentric_slope_at_vmax" More...

double	max_eccentric_velocity_force_multiplier
	"Curve value at the maximum normalized eccentric contraction velocity" More...

double	concentric_curviness
	"Concentric curve shape, from linear (0) to maximal curve (1)" More...

double	eccentric_curviness
	"Eccentric curve shape, from linear (0) to maximal curve (1)" More...

Public Member Functions
	ForceVelocityCurve ()
	The default constructor creates a force-velocity curve using the default property values and assigns a default name. More...

	ForceVelocityCurve (double concentricSlopeAtVmax, double concentricSlopeNearVmax, double isometricSlope, double eccentricSlopeAtVmax, double eccentricSlopeNearVmax, double maxEccentricVelocityForceMultiplier, double concentricCurviness, double eccentricCurviness)
	Constructs a force-velocity curve using the provided parameters and assigns a default name. More...

double	getConcentricSlopeAtVmax () const

double	getConcentricSlopeNearVmax () const

double	getIsometricSlope () const

double	getEccentricSlopeAtVmax () const

double	getEccentricSlopeNearVmax () const

double	getMaxEccentricVelocityForceMultiplier () const

double	getConcentricCurviness () const

double	getEccentricCurviness () const

void	setCurveShape (double aConcentricSlopeAtVmax, double aConcentricSlopeNearVmax, double aIsometricSlope, double aEccentricSlopeAtVmax, double aEccentricSlopeNearVmax, double aMaxForceMultiplier)
	More...

void	setConcentricCurviness (double aConcentricCurviness)
	More...

void	setEccentricCurviness (double aEccentricCurviness)
	More...

double	calcValue (const SimTK::Vector &x) const override
	Implement the generic OpenSim::Function interface. More...

double	calcValue (double normFiberVelocity) const
	Evaluates the force-velocity curve at a normalized fiber velocity of 'normFiberVelocity'. More...

double	calcDerivative (double normFiberVelocity, int order) const
	Calculates the derivative of the force-velocity multiplier with respect to the normalized fiber velocity. More...

double	calcDerivative (const std::vector< int > &derivComponents, const SimTK::Vector &x) const override
	If possible, use the simpler overload above. More...

SimTK::Vec2	getCurveDomain () const
	Returns a SimTK::Vec2 containing the lower (0th element) and upper (1st element) bounds on the domain of the curve. More...

void	printMuscleCurveToCSVFile (const std::string &path)
	Generates a .csv file with a name that matches the curve name (e.g., "bicepsfemoris_ForceVelocityCurve.csv"). More...

void	ensureCurveUpToDate ()

Property-related functions
const double &	get_concentric_slope_at_vmax () const
	Get the value of the concentric_slope_at_vmax property. More...

double &	upd_concentric_slope_at_vmax ()
	Get a writable reference to the concentric_slope_at_vmax property. More...

void	set_concentric_slope_at_vmax (const double &value)
	Set the value of the concentric_slope_at_vmax property. More...

const double &	get_concentric_slope_near_vmax () const
	Get the value of the concentric_slope_near_vmax property. More...

double &	upd_concentric_slope_near_vmax ()
	Get a writable reference to the concentric_slope_near_vmax property. More...

void	set_concentric_slope_near_vmax (const double &value)
	Set the value of the concentric_slope_near_vmax property. More...

const double &	get_isometric_slope () const
	Get the value of the isometric_slope property. More...

double &	upd_isometric_slope ()
	Get a writable reference to the isometric_slope property. More...

void	set_isometric_slope (const double &value)
	Set the value of the isometric_slope property. More...

const double &	get_eccentric_slope_at_vmax () const
	Get the value of the eccentric_slope_at_vmax property. More...

double &	upd_eccentric_slope_at_vmax ()
	Get a writable reference to the eccentric_slope_at_vmax property. More...

void	set_eccentric_slope_at_vmax (const double &value)
	Set the value of the eccentric_slope_at_vmax property. More...

const double &	get_eccentric_slope_near_vmax () const
	Get the value of the eccentric_slope_near_vmax property. More...

double &	upd_eccentric_slope_near_vmax ()
	Get a writable reference to the eccentric_slope_near_vmax property. More...

void	set_eccentric_slope_near_vmax (const double &value)
	Set the value of the eccentric_slope_near_vmax property. More...

const double &	get_max_eccentric_velocity_force_multiplier () const
	Get the value of the max_eccentric_velocity_force_multiplier property. More...

double &	upd_max_eccentric_velocity_force_multiplier ()
	Get a writable reference to the max_eccentric_velocity_force_multiplier property. More...

void	set_max_eccentric_velocity_force_multiplier (const double &value)
	Set the value of the max_eccentric_velocity_force_multiplier property. More...

const double &	get_concentric_curviness () const
	Get the value of the concentric_curviness property. More...

double &	upd_concentric_curviness ()
	Get a writable reference to the concentric_curviness property. More...

void	set_concentric_curviness (const double &value)
	Set the value of the concentric_curviness property. More...

const double &	get_eccentric_curviness () const
	Get the value of the eccentric_curviness property. More...

double &	upd_eccentric_curviness ()
	Get a writable reference to the eccentric_curviness property. More...

void	set_eccentric_curviness (const double &value)
	Set the value of the eccentric_curviness property. More...

Public Member Functions inherited from OpenSim::Function
	Function ()

	Function (const Function &aFunction)

virtual	~Function ()

virtual void	init (Function *aFunction)

Function &	operator= (const Function &aFunction)

virtual int	getArgumentSize () const
	Get the number of components expected in the input vector. More...

virtual int	getMaxDerivativeOrder () const
	Get the maximum derivative order this Function object can calculate. More...

Public Member Functions inherited from OpenSim::Object
virtual	~Object ()
	Virtual destructor for cleanup. More...

bool	isEqualTo (const Object &aObject) const
	Equality operator wrapper for use from languages not supporting operator overloading. More...

Object &	operator= (const Object &aObject)
	Copy assignment copies he base class fields, including the properties. More...

virtual bool	operator== (const Object &aObject) const
	Determine if two objects are equal. More...

virtual bool	operator< (const Object &aObject) const
	Provide an ordering for objects so they can be put in sorted containers. More...

void	setName (const std::string &name)
	Set the name of the Object. More...

const std::string &	getName () const
	Get the name of this Object. More...

void	setDescription (const std::string &description)
	Set description, a one-liner summary. More...

const std::string &	getDescription () const
	Get description, a one-liner summary. More...

const std::string &	getAuthors () const
	Get Authors of this Object. More...

void	setAuthors (const std::string &authors)
	Set Authors of this object. More...

const std::string &	getReferences () const
	Get references or publications to cite if using this object. More...

void	setReferences (const std::string &references)
	Set references or publications to cite if using this object. More...

int	getNumProperties () const
	Determine how many properties are stored with this Object. More...

const AbstractProperty &	getPropertyByIndex (int propertyIndex) const
	Get a const reference to a property by its index number, returned as an AbstractProperty. More...

AbstractProperty &	updPropertyByIndex (int propertyIndex)
	Get a writable reference to a property by its index number, returned as an AbstractProperty. More...

bool	hasProperty (const std::string &name) const
	Return true if this Object has a property of any type with the given name, which must not be empty. More...

const AbstractProperty &	getPropertyByName (const std::string &name) const
	Get a const reference to a property by its name, returned as an AbstractProperty. More...

AbstractProperty &	updPropertyByName (const std::string &name)
	Get a writable reference to a property by its name, returned as an AbstractProperty. More...

template<class T >
bool	hasProperty () const
	Return true if this Object contains an unnamed, one-object property that contains objects of the given template type T. More...

template<class T >
const Property< T > &	getProperty (const PropertyIndex &index) const
	Get property of known type Property<T> as a const reference; the property must be present and have the right type. More...

template<class T >
Property< T > &	updProperty (const PropertyIndex &index)
	Get property of known type Property<T> as a writable reference; the property must be present and have the right type. More...

bool	isObjectUpToDateWithProperties () const
	Returns `true` if no property's value has changed since the last time setObjectIsUpToDateWithProperties() was called. More...

void	readObjectFromXMLNodeOrFile (SimTK::Xml::Element &objectElement, int versionNumber)
	We're given an XML element from which we are to populate this Object. More...

virtual void	updateFromXMLNode (SimTK::Xml::Element &objectElement, int versionNumber)
	Use this method to deserialize an object from a SimTK::Xml::Element. More...

void	updateXMLNode (SimTK::Xml::Element &parent, const AbstractProperty *prop=nullptr) const
	Serialize this object into the XML node that represents it. More...

bool	getInlined () const
	Inlined means an in-memory Object that is not associated with an XMLDocument. More...

void	setInlined (bool aInlined, const std::string &aFileName="")
	Mark this as inlined or not and optionally provide a file name to associate with the new XMLDocument for the non-inline case. More...

std::string	getDocumentFileName () const
	If there is a document associated with this object then return the file name maintained by the document. More...

int	getDocumentFileVersion () const
	If there is a document associated with this object then return its version number. More...

void	setAllPropertiesUseDefault (bool aUseDefault)

bool	print (const std::string &fileName) const
	Write this Object into an XML file of the given name; conventionally the suffix to use is ".osim". More...

std::string	dump () const
	dump the XML representation of this Object into an std::string and return it. More...

virtual bool	isA (const char *type) const
	The default implementation returns true only if the supplied string is "Object"; each Object-derived class overrides this to match its own class name. More...

const std::string &	toString () const
	Wrapper to be used on Java side to display objects in tree; this returns just the object's name. More...

PropertySet &	getPropertySet ()
	OBSOLETE: Get a reference to the PropertySet maintained by the Object. More...

const PropertySet &	getPropertySet () const

Auto-generated functions
static ForceVelocityCurve *	safeDownCast (OpenSim::Object *obj)
	For use in MATLAB and Python to access the concrete class. More...

static const std::string &	getClassName ()
	This returns "ForceVelocityCurve". More...

ForceVelocityCurve *	clone () const override
	Create a new heap-allocated copy of the concrete object to which this Object refers. More...

const std::string &	getConcreteClassName () const override
	Returns the class name of the concrete Object-derived class of the actual object referenced by this Object, as a string. More...

Additional Inherited Members
Static Public Member Functions inherited from OpenSim::Function
static Function *	makeFunctionOfType (Function *aFunction, const std::string &aNewTypeName)

static Function *	safeDownCast (OpenSim::Object *obj)
	For use in MATLAB and Python to access the concrete class. More...

static const std::string &	getClassName ()
	This returns "Function". More...

Static Public Member Functions inherited from OpenSim::Object
static void	registerType (const Object &defaultObject)
	Register an instance of a class; if the class is already registered it will be replaced. More...

static void	renameType (const std::string &oldTypeName, const std::string &newTypeName)
	Support versioning by associating the current Object type with an old name. More...

static const Object *	getDefaultInstanceOfType (const std::string &concreteClassName)
	Return a pointer to the default instance of the registered (concrete) Object whose class name is given, or NULL if the type is not registered. More...

template<class T >
static bool	isObjectTypeDerivedFrom (const std::string &concreteClassName)
	Return true if the given concrete object type represents a subclass of the template object type T, and thus could be referenced with a T*. More...

static Object *	newInstanceOfType (const std::string &concreteClassName)
	Create a new instance of the concrete Object type whose class name is given as concreteClassName. More...

static void	getRegisteredTypenames (Array< std::string > &typeNames)
	Retrieve all the typenames registered so far. More...

template<class T >
static void	getRegisteredObjectsOfGivenType (ArrayPtrs< T > &rArray)
	Return an array of pointers to the default instances of all registered (concrete) Object types that derive from a given Object-derived type that does not have to be concrete. More...

static bool	PrintPropertyInfo (std::ostream &os, const std::string &classNameDotPropertyName, bool printFlagInfo=true)
	Dump formatted property information to a given output stream, useful for creating a "help" facility for registered objects. More...

static bool	PrintPropertyInfo (std::ostream &os, const std::string &className, const std::string &propertyName, bool printFlagInfo=true)
	Same as the other signature but the class name and property name are provided as two separate strings. More...

static Object *	makeObjectFromFile (const std::string &fileName)
	Create an OpenSim object whose type is based on the tag at the root node of the XML file passed in. More...

static const std::string &	getClassName ()
	Return the name of this class as a string; i.e., "Object". More...

static void	setSerializeAllDefaults (bool shouldSerializeDefaults)
	Static function to control whether all registered objects and their properties are written to the defaults section of output files rather than only those values for which the default was explicitly overwritten when read in from an input file or set programmatically. More...

static bool	getSerializeAllDefaults ()
	Report the value of the "serialize all defaults" flag. More...

static bool	isKindOf (const char *type)
	Returns true if the passed-in string is "Object"; each Object-derived class defines a method of this name for its own class name. More...

static void	setDebugLevel (int newLevel)
	Set the amount of logging output. More...

static int	getDebugLevel ()
	Get the current setting of debug level. More...

static Object *	SafeCopy (const Object *aObject)
	Use the clone() method to duplicate the given object unless the pointer is null in which case null is returned. More...

static void	RegisterType (const Object &defaultObject)
	OBSOLETE alternate name for registerType(). More...

static void	RenameType (const std::string &oldName, const std::string &newName)
	OBSOLETE alternate name for renameType(). More...

Detailed Description

This class serves as a serializable ForceVelocityCurve for use in muscle models.

The force-velocity curve is dimensionless: force is normalized to maximum isometric force and velocity is normalized to the maximum muscle contraction velocity (vmax), where vmax is expressed in units of optimal_fiber_lengths per second. Negative normalized velocities correspond to concentric contraction (i.e., shortening). The force-velocity curve is constructed from 8 properties:

Parameters

concentricSlopeAtVmax	The slope of the force-velocity curve at a normalized velocity of -1, which is the minimum slope of the concentric side of the force-velocity curve. A physiologically accurate value for this parameter is 0, though values greater than 0 are necessary when the force-velocity curve must be inverted.
concentricSlopeNearVmax	The slope of the force-velocity curve near the maximum normalized concentric (shortening) contraction velocity (between approximately -0.8 and -1).
isometricSlope	The slope of the force-velocity curve at a normalized velocity of 0, which is the maximum slope of the force-velocity curve. A physiologically accurate value for this parameter is 5 (according to Lieber, page 55), which is the default value. Although this parameter can be changed, it must be positive and greater than max( (maxEccentricMultiplier-1)/1, 1). The value of this parameter also affects how much the eccentric and concentric curves can be bent by the 'eccentricCurviness' and 'concentricCurviness' parameters, as it places an upper limit on the maximum slope of the force-velocity curve.
eccentricSlopeAtVmax	The slope of the force-velocity curve at a normalized velocity of 1, which is the minimum slope of the eccentric side of the force-velocity curve.
eccentricSlopeNearVmax	The slope of the force-velocity curve near the maximum normalized eccentric (lengthening) contraction velocity (between approximately 0.8 and 1).
maxEccentricVelocityForceMultiplier	The value of the force-velocity curve (i.e., the force-velocity multiplier) at the maximum eccentric contraction velocity. Physiologically accurate values for this parameter range between 1.1 and 1.8, and may vary between subjects.
concentricCurviness	A dimensionless parameter between 0 and 1 that describes the shape of the concentric curve: a value of 0 indicates that the curve is very close to a straight line segment and a value of 1 indicates a curve that smoothly fills the corner formed by the linear extrapolation of 'concentricSlopeNearVmax' and 'isometricSlope', as shown in the figure.
eccentricCurviness	A dimensionless parameter between 0 and 1 that describes the shape of the eccentric curve: a value of 0 indicates that the curve is very close to a straight line segment and a value of 1 indicates a curve that smoothly fills the corner formed by the linear extrapolation of 'isometricSlope' and 'eccentricSlopeNearVmax', as shown in the figure.

Conditions

 1)  0 <= concentricSlopeAtVmax < 1
2a)  1 < isometricSlope
2b)  (maxEccentricVelocityForceMultiplier-1)/1 < isometricMaxSlope
 3)  0 <= eccentricSlopeAtVmax < (maxEccentricVelocityForceMultiplier-1)/1
 4)  1 < maxEccentricVelocityForceMultiplier
 5)  0 <= concentricCurviness <= 1
 6)  0 <= eccentricCurviness <= 1

Default Parameter Values

concentricSlopeAtVmax .................. 0.0
concentricSlopeNearVmax ................ 0.25
isometricSlope ......................... 5.0
eccentricSlopeAtVmax ................... 0.0
eccentricSlopeNearVmax ................. 0.15
maxEccentricVelocityForceMultiplier .... 1.4
concentricCurviness .................... 0.6
eccentricCurviness ..................... 0.9

Example

ForceVelocityCurve fvCurve(0.0, 0.25, 5.0, 0.0, 0.15, 1.4, 0.6, 0.9);
double falVal  = fvCurve.calcValue(1.0);
double dfalVal = fvCurve.calcDerivative(1.0, 1);

References

Lieber, R.L. (2010) Skeletal Muscle Structure, Function, and Plasticity: The Physiological Basis of Rehabilitation, 3rd ed. Baltimore: Lippincott Williams & Wilkins.

Note that this object should be updated through the set methods provided. These set methods will take care of rebuilding the curve correctly. If you modify the properties directly, the curve will not be rebuilt, and upon calling a function like calcValue, calcDerivative, or printCurveToCSVFile, an exception will be thrown because the curve is out-of-date with its properties.

Author: Matt Millard

Constructor & Destructor Documentation

◆ ForceVelocityCurve() [1/2]

OpenSim::ForceVelocityCurve::ForceVelocityCurve ( )

The default constructor creates a force-velocity curve using the default property values and assigns a default name.

◆ ForceVelocityCurve() [2/2]

OpenSim::ForceVelocityCurve::ForceVelocityCurve	(	double	concentricSlopeAtVmax,
		double	concentricSlopeNearVmax,
		double	isometricSlope,
		double	eccentricSlopeAtVmax,
		double	eccentricSlopeNearVmax,
		double	maxEccentricVelocityForceMultiplier,
		double	concentricCurviness,
		double	eccentricCurviness
	)

Constructs a force-velocity curve using the provided parameters and assigns a default name.

Member Function Documentation

◆ calcDerivative() [1/2]

double OpenSim::ForceVelocityCurve::calcDerivative	(	double	normFiberVelocity,
		int	order
	)		const

Calculates the derivative of the force-velocity multiplier with respect to the normalized fiber velocity.

Parameters

normFiberVelocity	The normalized velocity of the muscle fiber.
order	The order of the derivative. Only values of 0, 1, and 2 are acceptable.

Returns: The derivative of the force-velocity curve with respect to the normalized fiber velocity.

◆ calcDerivative() [2/2]

double OpenSim::ForceVelocityCurve::calcDerivative	(	const std::vector< int > &	derivComponents,
		const SimTK::Vector &	x
	)		const

overridevirtual

If possible, use the simpler overload above.

Reimplemented from OpenSim::Function.

◆ calcValue() [1/2]

double OpenSim::ForceVelocityCurve::calcValue ( const SimTK::Vector & x ) const

inlineoverridevirtual

Implement the generic OpenSim::Function interface.

Reimplemented from OpenSim::Function.

◆ calcValue() [2/2]

double OpenSim::ForceVelocityCurve::calcValue ( double normFiberVelocity ) const

Evaluates the force-velocity curve at a normalized fiber velocity of 'normFiberVelocity'.

◆ clone()

ForceVelocityCurve* OpenSim::ForceVelocityCurve::clone ( ) const

inlineoverridevirtual

Create a new heap-allocated copy of the concrete object to which this Object refers.

It is up to the caller to delete the returned object when no longer needed. Every concrete object deriving from Object implements this pure virtual method automatically, via the declaration macro it invokes (e.g., OpenSim_DECLARE_CONCRETE_OBJECT()). Note that the concrete class overrides modify the return type to be a pointer to the concrete object; that still overrides the base class method because the return type is covariant with (that is, derives from) Object.

Implements OpenSim::Function.

◆ ensureCurveUpToDate()

void OpenSim::ForceVelocityCurve::ensureCurveUpToDate ( )

◆ get_concentric_curviness()

const double& OpenSim::ForceVelocityCurve::get_concentric_curviness ( ) const

inline

Get the value of the concentric_curviness property.

◆ get_concentric_slope_at_vmax()

const double& OpenSim::ForceVelocityCurve::get_concentric_slope_at_vmax ( ) const

inline

Get the value of the concentric_slope_at_vmax property.

◆ get_concentric_slope_near_vmax()

const double& OpenSim::ForceVelocityCurve::get_concentric_slope_near_vmax ( ) const

inline

Get the value of the concentric_slope_near_vmax property.

◆ get_eccentric_curviness()

const double& OpenSim::ForceVelocityCurve::get_eccentric_curviness ( ) const

inline

Get the value of the eccentric_curviness property.

◆ get_eccentric_slope_at_vmax()

const double& OpenSim::ForceVelocityCurve::get_eccentric_slope_at_vmax ( ) const

inline

Get the value of the eccentric_slope_at_vmax property.

◆ get_eccentric_slope_near_vmax()

const double& OpenSim::ForceVelocityCurve::get_eccentric_slope_near_vmax ( ) const

inline

Get the value of the eccentric_slope_near_vmax property.

◆ get_isometric_slope()

const double& OpenSim::ForceVelocityCurve::get_isometric_slope ( ) const

inline

Get the value of the isometric_slope property.

◆ get_max_eccentric_velocity_force_multiplier()

const double& OpenSim::ForceVelocityCurve::get_max_eccentric_velocity_force_multiplier ( ) const

inline

Get the value of the max_eccentric_velocity_force_multiplier property.

◆ getClassName()

static const std::string& OpenSim::ForceVelocityCurve::getClassName ( )

inlinestatic

This returns "ForceVelocityCurve".

See getConcreteClassName() if you want the class name of the underlying concrete object instead.

◆ getConcentricCurviness()

double OpenSim::ForceVelocityCurve::getConcentricCurviness ( ) const

Returns: A dimensionless parameter between 0 and 1 that describes the shape of the concentric curve: a value of 0 indicates that the curve is very close to a straight line segment and a value of 1 indicates a curve that smoothly fills the corner formed by the linear extrapolation of 'concentricSlopeNearVmax' and 'isometricSlope', as shown in the figure in the class description.

◆ getConcentricSlopeAtVmax()

double OpenSim::ForceVelocityCurve::getConcentricSlopeAtVmax ( ) const

Returns: The slope of the force-velocity curve at a normalized velocity of -1, which is the minimum slope of the concentric side of the force-velocity curve.

◆ getConcentricSlopeNearVmax()

double OpenSim::ForceVelocityCurve::getConcentricSlopeNearVmax ( ) const

Returns: The slope of the force-velocity curve near the maximum normalized concentric (shortening) contraction velocity (between approximately -0.8 and -1).

◆ getConcreteClassName()

const std::string& OpenSim::ForceVelocityCurve::getConcreteClassName ( ) const

inlineoverridevirtual

Returns the class name of the concrete Object-derived class of the actual object referenced by this Object, as a string.

This is the string that is used as the tag for this concrete object in an XML file. Every concrete class derived from Object automatically overrides this method via the declaration macro it uses. See getClassName() to get the class name of the referencing (possibly abstract) class rather than the concrete object.

See also: getClassName()

Implements OpenSim::Function.

◆ getCurveDomain()

SimTK::Vec2 OpenSim::ForceVelocityCurve::getCurveDomain ( ) const

Returns a SimTK::Vec2 containing the lower (0th element) and upper (1st element) bounds on the domain of the curve.

Outside this domain, the curve is approximated using linear extrapolation.

Returns: The minimum and maximum value of the domain, x, of the curve y(x). Within this range, y(x) is a curve; outside this range, the function y(x) is a C2-continuous linear extrapolation.

◆ getEccentricCurviness()

double OpenSim::ForceVelocityCurve::getEccentricCurviness ( ) const

Returns: A dimensionless parameter between 0 and 1 that describes the shape of the eccentric curve: a value of 0 indicates that the curve is very close to a straight line segment and a value of 1 indicates a curve that smoothly fills the corner formed by the linear extrapolation of 'isometricSlope' and 'eccentricSlopeNearVmax', as shown in the figure in the class description.

◆ getEccentricSlopeAtVmax()

double OpenSim::ForceVelocityCurve::getEccentricSlopeAtVmax ( ) const

Returns: The slope of the force-velocity curve at a normalized velocity of 1, which is the minimum slope of the eccentric side of the force-velocity curve.

◆ getEccentricSlopeNearVmax()

double OpenSim::ForceVelocityCurve::getEccentricSlopeNearVmax ( ) const

Returns: The slope of the force-velocity curve near the maximum normalized eccentric (lengthening) contraction velocity (between approximately 0.8 and 1).

◆ getIsometricSlope()

double OpenSim::ForceVelocityCurve::getIsometricSlope ( ) const

Returns: The slope of the force-velocity curve at a normalized velocity of 0, which is the maximum slope of the force-velocity curve.

◆ getMaxEccentricVelocityForceMultiplier()

double OpenSim::ForceVelocityCurve::getMaxEccentricVelocityForceMultiplier ( ) const

Returns: The value of the force-velocity curve (i.e., the force-velocity multiplier) at the maximum eccentric contraction velocity.

◆ printMuscleCurveToCSVFile()

void OpenSim::ForceVelocityCurve::printMuscleCurveToCSVFile ( const std::string & path )

Generates a .csv file with a name that matches the curve name (e.g., "bicepsfemoris_ForceVelocityCurve.csv").

This function is not const to permit the curve to be rebuilt if it is out-of-date with its properties.

Parameters

path	The full destination path. Note that forward slashes ('/') must be used and there should not be a slash after the last folder.

The file will contain the following data:

column: 1 | 2 |     3 |       4
  data: x | y | dy/dx | d2y/dx2

Samples will be taken from the concentric linear extrapolation region (the region with normalized fiber velocities < -1), through the curve, out to the eccentric linear extrapolation region (the region with normalized fiber velocities > 1). The width of each linear extrapolation region is 10% of the curve domain, or 0.1*(x1-x0). The curve is sampled quite densely: the force-velocity .csv file will have 200+20 rows.

Example To read the .csv file into Matlab, you need to set csvread to ignore the header row. Since csvread is 0-indexed, the following example will begin reading the .csv file from the first column of the second row:

data = csvread('bicepsfemoris_ForceVelocityCurve.csv', 1, 0);

◆ safeDownCast()

static ForceVelocityCurve* OpenSim::ForceVelocityCurve::safeDownCast ( OpenSim::Object * obj )

inlinestatic

For use in MATLAB and Python to access the concrete class.

Example: cObj = ForceVelocityCurve.safeDownCast(obj). This is equivalent to dynamic_cast<ForceVelocityCurve*>(obj) in C++.

◆ set_concentric_curviness()

void OpenSim::ForceVelocityCurve::set_concentric_curviness ( const double & value )

inline

Set the value of the concentric_curviness property.

◆ set_concentric_slope_at_vmax()

void OpenSim::ForceVelocityCurve::set_concentric_slope_at_vmax ( const double & value )

inline

Set the value of the concentric_slope_at_vmax property.

◆ set_concentric_slope_near_vmax()

void OpenSim::ForceVelocityCurve::set_concentric_slope_near_vmax ( const double & value )

inline

Set the value of the concentric_slope_near_vmax property.

◆ set_eccentric_curviness()

void OpenSim::ForceVelocityCurve::set_eccentric_curviness ( const double & value )

inline

Set the value of the eccentric_curviness property.

◆ set_eccentric_slope_at_vmax()

void OpenSim::ForceVelocityCurve::set_eccentric_slope_at_vmax ( const double & value )

inline

Set the value of the eccentric_slope_at_vmax property.

◆ set_eccentric_slope_near_vmax()

void OpenSim::ForceVelocityCurve::set_eccentric_slope_near_vmax ( const double & value )

inline

Set the value of the eccentric_slope_near_vmax property.

◆ set_isometric_slope()

void OpenSim::ForceVelocityCurve::set_isometric_slope ( const double & value )

inline

Set the value of the isometric_slope property.

◆ set_max_eccentric_velocity_force_multiplier()

void OpenSim::ForceVelocityCurve::set_max_eccentric_velocity_force_multiplier ( const double & value )

inline

Set the value of the max_eccentric_velocity_force_multiplier property.

◆ setConcentricCurviness()

void OpenSim::ForceVelocityCurve::setConcentricCurviness ( double aConcentricCurviness )

Parameters

aConcentricCurviness A dimensionless parameter between 0 and 1 that describes the shape of the concentric curve: a value of 0 indicates that the curve is very close to a straight line segment and a value of 1 indicates a curve that smoothly fills the corner formed by the linear extrapolation of 'concentricSlopeNearVmax' and 'isometricSlope', as shown in the figure in the class description.

Conditions

0 <= concentricCurviness <= 1

◆ setCurveShape()

void OpenSim::ForceVelocityCurve::setCurveShape	(	double	aConcentricSlopeAtVmax,
		double	aConcentricSlopeNearVmax,
		double	aIsometricSlope,
		double	aEccentricSlopeAtVmax,
		double	aEccentricSlopeNearVmax,
		double	aMaxForceMultiplier
	)

Parameters

aConcentricSlopeAtVmax	The slope of the force-velocity curve at a normalized velocity of -1, which is the minimum slope of the concentric side of the force-velocity curve.
aConcentricSlopeNearVmax	The slope of the force-velocity curve near the maximum normalized concentric (shortening) contraction velocity (between approximately -0.8 and -1).
aIsometricSlope	The slope of the force-velocity curve at a normalized velocity of 0, which is the maximum slope of the force-velocity curve.
aEccentricSlopeAtVmax	The slope of the force-velocity curve at a normalized velocity of 1, which is the minimum slope of the eccentric side of the force-velocity curve.
aEccentricSlopeNearVmax	The slope of the force-velocity curve near the maximum normalized eccentric (lengthening) contraction velocity (between approximately 0.8 and 1).
aMaxForceMultiplier	The value of the force-velocity curve (i.e., the force-velocity multiplier) at the maximum eccentric contraction velocity.

Conditions

1a)  0 <= concentricSlopeAtVmax < 1
1b)  concentricSlopeAtVmax < concentricSlopeNearVmax < 1
2a)  1 < isometricSlope
2b)  (maxEccentricVelocityForceMultiplier-1)/1 < isometricMaxSlope
3a)  0 <= eccentricSlopeAtVmax < (maxEccentricVelocityForceMultiplier-1)/1
3b)  eccentricSlopeAtVmax < eccentricSlopeNearVmax < (maxEccentricVelocityForceMultiplier-1)/1
 4)  1 < maxEccentricVelocityForceMultiplier

◆ setEccentricCurviness()

void OpenSim::ForceVelocityCurve::setEccentricCurviness ( double aEccentricCurviness )

Parameters

aEccentricCurviness A dimensionless parameter between 0 and 1 that describes the shape of the eccentric curve: a value of 0 indicates that the curve is very close to a straight line segment and a value of 1 indicates a curve that smoothly fills the corner formed by the linear extrapolation of 'isometricSlope' and 'eccentricSlopeNearVmax', as shown in the figure in the class description.

Conditions

0 <= eccentricCurviness <= 1

◆ upd_concentric_curviness()

double& OpenSim::ForceVelocityCurve::upd_concentric_curviness ( )

inline

Get a writable reference to the concentric_curviness property.

◆ upd_concentric_slope_at_vmax()

double& OpenSim::ForceVelocityCurve::upd_concentric_slope_at_vmax ( )

inline

Get a writable reference to the concentric_slope_at_vmax property.

◆ upd_concentric_slope_near_vmax()

double& OpenSim::ForceVelocityCurve::upd_concentric_slope_near_vmax ( )

inline

Get a writable reference to the concentric_slope_near_vmax property.

◆ upd_eccentric_curviness()

double& OpenSim::ForceVelocityCurve::upd_eccentric_curviness ( )

inline

Get a writable reference to the eccentric_curviness property.

◆ upd_eccentric_slope_at_vmax()

double& OpenSim::ForceVelocityCurve::upd_eccentric_slope_at_vmax ( )

inline

Get a writable reference to the eccentric_slope_at_vmax property.

◆ upd_eccentric_slope_near_vmax()

double& OpenSim::ForceVelocityCurve::upd_eccentric_slope_near_vmax ( )

inline

Get a writable reference to the eccentric_slope_near_vmax property.

◆ upd_isometric_slope()

double& OpenSim::ForceVelocityCurve::upd_isometric_slope ( )

inline

Get a writable reference to the isometric_slope property.

◆ upd_max_eccentric_velocity_force_multiplier()

double& OpenSim::ForceVelocityCurve::upd_max_eccentric_velocity_force_multiplier ( )

inline

Get a writable reference to the max_eccentric_velocity_force_multiplier property.

OpenSim Property, Socket, Output, Input Documentation

◆ concentric_curviness

double OpenSim::ForceVelocityCurve::concentric_curviness

"Concentric curve shape, from linear (0) to maximal curve (1)"

This property appears in XML files under the tag <concentric_curviness>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also: get_concentric_curviness(), upd_concentric_curviness(), set_concentric_curviness()

◆ concentric_slope_at_vmax

double OpenSim::ForceVelocityCurve::concentric_slope_at_vmax

"Curve slope at the maximum normalized concentric (shortening) velocity (normalized velocity of -1)"

This property appears in XML files under the tag <concentric_slope_at_vmax>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also: get_concentric_slope_at_vmax(), upd_concentric_slope_at_vmax(), set_concentric_slope_at_vmax()

◆ concentric_slope_near_vmax

double OpenSim::ForceVelocityCurve::concentric_slope_near_vmax

"Curve slope just before reaching concentric_slope_at_vmax"

This property appears in XML files under the tag <concentric_slope_near_vmax>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also: get_concentric_slope_near_vmax(), upd_concentric_slope_near_vmax(), set_concentric_slope_near_vmax()

◆ eccentric_curviness

double OpenSim::ForceVelocityCurve::eccentric_curviness

"Eccentric curve shape, from linear (0) to maximal curve (1)"

This property appears in XML files under the tag <eccentric_curviness>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also: get_eccentric_curviness(), upd_eccentric_curviness(), set_eccentric_curviness()

◆ eccentric_slope_at_vmax

double OpenSim::ForceVelocityCurve::eccentric_slope_at_vmax

"Curve slope at the maximum normalized eccentric (lengthening) velocity (normalized velocity of 1)"

This property appears in XML files under the tag <eccentric_slope_at_vmax>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also: get_eccentric_slope_at_vmax(), upd_eccentric_slope_at_vmax(), set_eccentric_slope_at_vmax()

◆ eccentric_slope_near_vmax

double OpenSim::ForceVelocityCurve::eccentric_slope_near_vmax

"Curve slope just before reaching eccentric_slope_at_vmax"

This property appears in XML files under the tag <eccentric_slope_near_vmax>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also: get_eccentric_slope_near_vmax(), upd_eccentric_slope_near_vmax(), set_eccentric_slope_near_vmax()

◆ isometric_slope

double OpenSim::ForceVelocityCurve::isometric_slope

"Curve slope at isometric (normalized velocity of 0)"

This property appears in XML files under the tag <isometric_slope>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also: get_isometric_slope(), upd_isometric_slope(), set_isometric_slope()

◆ max_eccentric_velocity_force_multiplier

double OpenSim::ForceVelocityCurve::max_eccentric_velocity_force_multiplier

"Curve value at the maximum normalized eccentric contraction velocity"

This property appears in XML files under the tag <max_eccentric_velocity_force_multiplier>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.

See also: get_max_eccentric_velocity_force_multiplier(), upd_max_eccentric_velocity_force_multiplier(), set_max_eccentric_velocity_force_multiplier()

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

OpenSim/Actuators/ForceVelocityCurve.h

OpenSim Properties, Sockets, Outputs, Inputs

Public Member Functions

Auto-generated functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ ForceVelocityCurve() [1/2]

◆ ForceVelocityCurve() [2/2]

Member Function Documentation

◆ calcDerivative() [1/2]

◆ calcDerivative() [2/2]

◆ calcValue() [1/2]

◆ calcValue() [2/2]

◆ clone()

◆ ensureCurveUpToDate()

◆ get_concentric_curviness()

◆ get_concentric_slope_at_vmax()

◆ get_concentric_slope_near_vmax()

◆ get_eccentric_curviness()

◆ get_eccentric_slope_at_vmax()

◆ get_eccentric_slope_near_vmax()

◆ get_isometric_slope()

◆ get_max_eccentric_velocity_force_multiplier()

◆ getClassName()

◆ getConcentricCurviness()

◆ getConcentricSlopeAtVmax()

◆ getConcentricSlopeNearVmax()

◆ getConcreteClassName()

◆ getCurveDomain()

◆ getEccentricCurviness()

◆ getEccentricSlopeAtVmax()

◆ getEccentricSlopeNearVmax()

◆ getIsometricSlope()

◆ getMaxEccentricVelocityForceMultiplier()

◆ printMuscleCurveToCSVFile()

◆ safeDownCast()

◆ set_concentric_curviness()

◆ set_concentric_slope_at_vmax()

◆ set_concentric_slope_near_vmax()

◆ set_eccentric_curviness()

◆ set_eccentric_slope_at_vmax()

◆ set_eccentric_slope_near_vmax()

◆ set_isometric_slope()

◆ set_max_eccentric_velocity_force_multiplier()

◆ setConcentricCurviness()

◆ setCurveShape()

◆ setEccentricCurviness()

◆ upd_concentric_curviness()

◆ upd_concentric_slope_at_vmax()

◆ upd_concentric_slope_near_vmax()

◆ upd_eccentric_curviness()

◆ upd_eccentric_slope_at_vmax()

◆ upd_eccentric_slope_near_vmax()

◆ upd_isometric_slope()

◆ upd_max_eccentric_velocity_force_multiplier()

OpenSim Property, Socket, Output, Input Documentation

◆ concentric_curviness

◆ concentric_slope_at_vmax

◆ concentric_slope_near_vmax

◆ eccentric_curviness

◆ eccentric_slope_at_vmax

◆ eccentric_slope_near_vmax

◆ isometric_slope

◆ max_eccentric_velocity_force_multiplier