API  4.5
For C++ developers
OpenSim::FiberCompressiveForceLengthCurve Class Reference


This class serves as a serializable FiberCompressiveForceLengthCurve, which is used to ensure that the fiber cannot generate force at, nor shorten beyond a minimum normalized length. More...

+ Inheritance diagram for OpenSim::FiberCompressiveForceLengthCurve:

OpenSim Properties, Sockets, Outputs, Inputs

Properties (single-value)
double norm_length_at_zero_force
 "Normalized fiber length at zero force" More...
 
Properties (optional)
double stiffness_at_zero_length
 "Fiber stiffness at zero length" More...
 
double curviness
 "Fiber curve bend, from linear to maximum bend (0-1)" More...
 

Public Member Functions

 FiberCompressiveForceLengthCurve ()
 Default constructor creates an object with a default name that doesn't yet define a curve. More...
 
 FiberCompressiveForceLengthCurve (double normLengthAtZeroForce, double stiffnessAtZeroLength, double curviness, const std::string &muscleName)
 Constructs a C2 continuous compressive fiber force length curve. More...
 
double getNormLengthAtZeroForce () const
 
More...
 
double getStiffnessAtZeroLengthInUse () const
 
More...
 
double getCurvinessInUse () const
 
More...
 
void setNormLengthAtZeroForce (double aNormLengthAtZeroForce)
 
More...
 
void setOptionalProperties (double aStiffnessAtZeroLength, double aCurviness)
 
More...
 
bool isFittedCurveBeingUsed () const
 
More...
 
double calcValue (double aNormLength) const
 
Calculates the value of the curve evaluated at the desired normalized fiber length. More...
 
double calcValue (const SimTK::Vector &x) const override
 Implement the generic OpenSim::Function interface. More...
 
double calcDerivative (double aNormLength, int order) const
 
Calculates the derivative of the fiber force length curve w.r.t. More...
 
double calcDerivative (const std::vector< int > &derivComponents, const SimTK::Vector &x) const override
 If possible, use the simpler overload above. More...
 
double calcIntegral (double aNormLength) const
 
More...
 
SimTK::Vec2 getCurveDomain () const
 This function returns a SimTK::Vec2 that contains in its 0th element the lowest value of the curve domain, and in its 1st element the highest value in the curve domain of the curve. More...
 
void printMuscleCurveToCSVFile (const std::string &path)
 This function will generate a csv file with a name that matches the curve name (e.g. More...
 
void ensureCurveUpToDate ()
 
Property-related functions
const double & get_norm_length_at_zero_force () const
 Get the value of the norm_length_at_zero_force property. More...
 
double & upd_norm_length_at_zero_force ()
 Get a writable reference to the norm_length_at_zero_force property. More...
 
void set_norm_length_at_zero_force (const double &value)
 Set the value of the norm_length_at_zero_force property. More...
 
const double & get_stiffness_at_zero_length () const
 Get the value of the stiffness_at_zero_length property. More...
 
double & upd_stiffness_at_zero_length ()
 Get a writable reference to the stiffness_at_zero_length property. More...
 
void set_stiffness_at_zero_length (const double &value)
 Set the value of the stiffness_at_zero_length property. More...
 
const double & get_curviness () const
 Get the value of the curviness property. More...
 
double & upd_curviness ()
 Get a writable reference to the curviness property. More...
 
void set_curviness (const double &value)
 Set the value of the curviness property. More...
 
- Public Member Functions inherited from OpenSim::Function
 Function ()
 
 Function (const Function &aFunction)
 
virtual ~Function ()
 
virtual void init (Function *aFunction)
 
Functionoperator= (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...
 
void assign (Object &aObject) override
 This allows copy assignment in the Java GUI. 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...
 
Objectoperator= (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 AbstractPropertygetPropertyByIndex (int propertyIndex) const
 Get a const reference to a property by its index number, returned as an AbstractProperty. More...
 
AbstractPropertyupdPropertyByIndex (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 AbstractPropertygetPropertyByName (const std::string &name) const
 Get a const reference to a property by its name, returned as an AbstractProperty. More...
 
AbstractPropertyupdPropertyByName (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 >
const Property< T > & getPropertyByName (const std::string &name) 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...
 
template<class T >
Property< T > & updPropertyByName (const std::string &name)
 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...
 
PropertySetgetPropertySet ()
 OBSOLETE: Get a reference to the PropertySet maintained by the Object. More...
 
const PropertySetgetPropertySet () const
 

Public Types

typedef FiberCompressiveForceLengthCurve Self
 This typedef might be useful within the member functions of this class. More...
 
typedef Function Super
 Use this typedef to refer to the superclass of this class. More...
 
- Public Types inherited from OpenSim::Function
typedef Function Self
 This typedef might be useful within the member functions of this class. More...
 
typedef Object Super
 Use this typedef to refer to the superclass of this class. More...
 

Auto-generated functions

static FiberCompressiveForceLengthCurvesafeDownCast (OpenSim::Object *obj)
 For use in MATLAB and Python to access the concrete class. More...
 
static const std::string & getClassName ()
 This returns "FiberCompressiveForceLengthCurve". More...
 
void assign (Object &aObject) override
 This allows copy assignment in the Java GUI. More...
 
FiberCompressiveForceLengthCurveclone () 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 FunctionmakeFunctionOfType (Function *aFunction, const std::string &aNewTypeName)
 
static FunctionsafeDownCast (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 ObjectgetDefaultInstanceOfType (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 ObjectnewInstanceOfType (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 ObjectmakeObjectFromFile (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 ObjectSafeCopy (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...
 
- Static Public Attributes inherited from OpenSim::Object
static const std::string DEFAULT_NAME
 Name used for default objects when they are serialized. More...
 
- Protected Member Functions inherited from OpenSim::Function
void resetFunction ()
 This should be called whenever this object has been modified. More...
 
- Protected Member Functions inherited from OpenSim::Object
 Object ()
 The default constructor is only for use by constructors of derived types. More...
 
 Object (const std::string &fileName, bool aUpdateFromXMLNode=true)
 Constructor from a file, to be called from other constructors that take a file as input. More...
 
 Object (const Object &source)
 Copy constructor is invoked automatically by derived classes with default copy constructors; otherwise it must be invoked explicitly. More...
 
 Object (SimTK::Xml::Element &aElement)
 Construct the base class portion of an Object from a given Xml element that describes this Object. More...
 
template<class T >
PropertyIndex addProperty (const std::string &name, const std::string &comment, const T &value)
 Define a new single-value property of known type T, with the given name, associated comment, and initial value. More...
 
template<class T >
PropertyIndex addOptionalProperty (const std::string &name, const std::string &comment)
 Add an optional property, meaning it can contain either no value or a single value. More...
 
template<class T >
PropertyIndex addOptionalProperty (const std::string &name, const std::string &comment, const T &value)
 Add an optional property, meaning it can contain either no value or a single value. More...
 
template<class T >
PropertyIndex addListProperty (const std::string &name, const std::string &comment, int minSize, int maxSize)
 Define a new list-valued property of known type T, with the given name, associated comment, minimum (==0) and maximum (>0) allowable list lengths, and a zero-length initial value. More...
 
template<class T , template< class > class Container>
PropertyIndex addListProperty (const std::string &name, const std::string &comment, int minSize, int maxSize, const Container< T > &valueList)
 Define a new list-valued property as above, but assigning an initial value via some templatized container class that supports size() and indexing. More...
 
PropertyIndex getPropertyIndex (const std::string &name) const
 Look up a property by name and return its PropertyIndex if it is found. More...
 
template<class T >
PropertyIndex getPropertyIndex () const
 Look up an unnamed property by the type of object it contains, and return its PropertyIndex if it is found. More...
 
template<class T >
void checkPropertyValueIsPositive (const Property< T > &p) const
 Throw an exception if any of the property's values are not positive. More...
 
template<class T >
void checkPropertyValueIsInSet (const Property< T > &p, const std::set< T > &set) const
 Throw an exception if any of the property's values are not in the provided set. More...
 
template<class T >
void checkPropertyValueIsInRangeOrSet (const Property< T > &p, const T &lower, const T &upper, const std::set< T > &set) const
 Throw an exception if any of the property's values are neither in the provided range nor in the provided set. More...
 
void setObjectIsUpToDateWithProperties ()
 When an object is initialized using the current values of its properties, it can set a flag indicating that it is up to date. More...
 
void clearObjectIsUpToDateWithProperties ()
 For testing or debugging purposes, manually clear the "object is up to date with respect to properties" flag. More...
 
void makeObjectNamesConsistentWithProperties ()
 Make sure the name of an object is consistent with its property type. More...
 
void updateFromXMLDocument ()
 Use this method only if you're deserializing from a file and the object is at the top level; that is, primarily in constructors that take a file name as input. More...
 
void setDocument (XMLDocument *doc)
 Unconditionally set the XMLDocument associated with this object. More...
 
const XMLDocumentgetDocument () const
 Get a const pointer to the document (if any) associated with this object. More...
 
XMLDocumentupdDocument ()
 Get a writable pointer to the document (if any) associated with this object. More...
 
- Protected Attributes inherited from OpenSim::Function
SimTK::Function * _function
 
- Protected Attributes inherited from OpenSim::Object
PropertySet _propertySet
 OBSOLETE: Property_Deprecated set for serializable member variables of this and derived classes. More...
 

Detailed Description


This class serves as a serializable FiberCompressiveForceLengthCurve, which is used to ensure that the fiber cannot generate force at, nor shorten beyond a minimum normalized length.

fig_FiberCompressiveForceLengthCurve.png

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

Member Typedef Documentation

◆ Self

This typedef might be useful within the member functions of this class.

This is generated by the OpenSim_DECLARE_*_OBJECT macros.

◆ Super

Use this typedef to refer to the superclass of this class.

Avoid using the explicit type name of the superclass; this would introduce bugs if the superclass is changed.

This is generated by the OpenSim_DECLARE_*_OBJECT macros.

Constructor & Destructor Documentation

◆ FiberCompressiveForceLengthCurve() [1/2]

OpenSim::FiberCompressiveForceLengthCurve::FiberCompressiveForceLengthCurve ( )

Default constructor creates an object with a default name that doesn't yet define a curve.

◆ FiberCompressiveForceLengthCurve() [2/2]

OpenSim::FiberCompressiveForceLengthCurve::FiberCompressiveForceLengthCurve ( double  normLengthAtZeroForce,
double  stiffnessAtZeroLength,
double  curviness,
const std::string &  muscleName 
)

Constructs a C2 continuous compressive fiber force length curve.

This curve is used in the fiber model as a means of ensuring that the fiber cannot generate a tensile force at, nor shorten beyond, some minimum length. Details to appear in Millard et al. 2012.

Parameters
normLengthAtZeroForceThe normalized fiber length at which the compressive element begins to engage. Normalized length is defined as length_norm = l/l0, where l is the length of the fiber, and l0 is the resting length of the fiber.
stiffnessAtZeroLengthThis is the stiffness of the compressive elastic force length spring when the fiber reaches a normalized length of 0.
curvinessA dimensionless parameter between [0-1] that controls how the curve is drawn: 0 will create a curve that is very close to a straight line segment while a value of 1 will create a curve that smoothly fills the corner formed by the linear extrapolation of 'stiffnessAtZeroLength' and the x axis as shown in the figure.
muscleNameThe name of the muscle this curve belongs to. This name is used to create the name of this curve, which is formed simply by appending "_FiberCompressiveForceLengthCurve" to the string in muscleName. This name is used for making intelligible error messages and also for naming the XML version of this curve when it is serialized.

Conditions

    normLengthAtZeroForce > 0
    stiffnessAtZeroLength < -1/normLengthAtZeroForce
    0 <= curviness <= 1

Computational Costs

    ~174,100 flops

Default Parameter Values

    normLengthAtZeroForce   = 0.6
    stiffnessAtZeroLength   = -8.4
    curviness               = 0.5

Member Function Documentation

◆ assign()

void OpenSim::FiberCompressiveForceLengthCurve::assign ( Object aObject)
inlineoverride

This allows copy assignment in the Java GUI.

Exceptions
Exceptionif the argument is not of type FiberCompressiveForceLengthCurve.

◆ calcDerivative() [1/2]

double OpenSim::FiberCompressiveForceLengthCurve::calcDerivative ( double  aNormLength,
int  order 
) const


Calculates the derivative of the fiber force length curve w.r.t.

to the normalized fiber length.

Parameters
aNormLengthThe normalized fiber length used to evaluate the compressive fiber force length curve for the corresponding normalized force. Here aNormLength = l/l0, where l is the length of the fiber and l0 is the resting length of the fiber. Thus normalized length of 1.0 means the fiber is at its resting length.
orderthe order of the derivative. Only values of 0,1 and 2 are acceptable.
Returns
the derivative of the normalized fiber force length curve w.r.t. normalized fiber length

Computational Costs

    x in curve domain  : ~391 flops
    x in linear section:   ~2 flops       

◆ calcDerivative() [2/2]

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

If possible, use the simpler overload above.

Reimplemented from OpenSim::Function.

◆ calcIntegral()

double OpenSim::FiberCompressiveForceLengthCurve::calcIntegral ( double  aNormLength) const


Parameters
aNormLengthHere aNormLength = l/l0, where l is the length of the fiber and l0 is the resting length of the fiber.
Thus normalized length of 1.0 means the fiber is at its resting length.
Returns
Computes the normalized area under the curve. For this curve, this quantity corresponds to the normalized potential energy stored in the fiber compressive force length spring - simply multiply this quantity by the number of NormForce*NormDistance (where NormForce corresponds to the number of Newtons that 1 normalized force corresponds to, and NormDistance is the distance in meters that a normalized value of 1 corresponds to) to obtain the potential energy stored in the fiber in units of Joules.

Computational Costs

    x in curve domain  : ~13 flops
    x in linear section: ~19 flops

◆ calcValue() [1/2]

double OpenSim::FiberCompressiveForceLengthCurve::calcValue ( double  aNormLength) const


Calculates the value of the curve evaluated at the desired normalized fiber length.

Parameters
aNormLengthThe normalized fiber length used to evaluate the fiber compressive force length curve for the corresponding normalized force. Here aNormLength = l/l0, where l is the length of the fiber and l0 is the resting length of the fiber. Thus normalized length of 1.0 means the fiber is at its resting length.
Returns
the value of the normalized force generated by the fiber

Computational Costs

    x in curve domain  : ~282 flops
    x in linear section:   ~5 flops

◆ calcValue() [2/2]

double OpenSim::FiberCompressiveForceLengthCurve::calcValue ( const SimTK::Vector &  x) const
inlineoverridevirtual

Implement the generic OpenSim::Function interface.

Reimplemented from OpenSim::Function.

◆ clone()

FiberCompressiveForceLengthCurve* OpenSim::FiberCompressiveForceLengthCurve::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::FiberCompressiveForceLengthCurve::ensureCurveUpToDate ( )

◆ get_curviness()

const double& OpenSim::FiberCompressiveForceLengthCurve::get_curviness ( ) const
inline

Get the value of the curviness property.

◆ get_norm_length_at_zero_force()

const double& OpenSim::FiberCompressiveForceLengthCurve::get_norm_length_at_zero_force ( ) const
inline

Get the value of the norm_length_at_zero_force property.

◆ get_stiffness_at_zero_length()

const double& OpenSim::FiberCompressiveForceLengthCurve::get_stiffness_at_zero_length ( ) const
inline

Get the value of the stiffness_at_zero_length property.

◆ getClassName()

static const std::string& OpenSim::FiberCompressiveForceLengthCurve::getClassName ( )
inlinestatic

This returns "FiberCompressiveForceLengthCurve".

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

This is generated by the OpenSim_DECLARE_*_OBJECT macros.

◆ getConcreteClassName()

const std::string& OpenSim::FiberCompressiveForceLengthCurve::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::FiberCompressiveForceLengthCurve::getCurveDomain ( ) const

This function returns a SimTK::Vec2 that contains in its 0th element the lowest value of the curve domain, and in its 1st element the highest value in the curve domain of the curve.

Outside of 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 of this range the function y(x) is a C2 (continuous to the second derivative) linear extrapolation

◆ getCurvinessInUse()

double OpenSim::FiberCompressiveForceLengthCurve::getCurvinessInUse ( ) const


Returns
A dimensionless parameter between [0-1] that controls how the curve is drawn: 0 will create a curve that is very close to a straight line segment while a value of 1 will create a curve that smoothly fills the corner formed by the linear extrapolation of 'stiffnessAtOneNormForce' and the x axis as shown in the figure. If this optional property is not specified, a suitable value will be calculated and used instead.

◆ getNormLengthAtZeroForce()

double OpenSim::FiberCompressiveForceLengthCurve::getNormLengthAtZeroForce ( ) const


Returns
The normalized fiber length at which the compressive element begins to engage. Normalized length is defined as length_norm = l/l0, where l is the length of the fiber, and l0 is the resting length of the fiber.

◆ getStiffnessAtZeroLengthInUse()

double OpenSim::FiberCompressiveForceLengthCurve::getStiffnessAtZeroLengthInUse ( ) const


Returns
This is the stiffness of the compressive elastic force length spring when the fiber reaches a normalized length of 0. If this optional property is not specified, a suitable value will be calculated and used instead.

◆ isFittedCurveBeingUsed()

bool OpenSim::FiberCompressiveForceLengthCurve::isFittedCurveBeingUsed ( ) const


Returns
true if the optional properties are empty and the fitted curve is being used. This function returns false if the optional properties are filled and are being used to construct the curve.

◆ printMuscleCurveToCSVFile()

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

This function will generate a csv file with a name that matches the curve name (e.g.

"bicepfemoris_FiberCompressiveForceLengthCurve.csv"); This function is not const to permit the curve to be rebuilt if it is out of date with its properties.

Parameters
pathThe full path to the location. Note '/' slashes must be used, and do not put a '/' after the last folder.

The file will contain the following columns:

Col# 1, 2,     3,       4,  
     x, y, dy/dx, d2y/dx2,

The curve will be sampled from its linear extrapolation region (the region with normalized fiber velocities < -1), through the curve, out to the other linear extrapolation region (the region with normalized fiber velocities > 1). The width of each linear extrapolation region is 10% of the entire range of x, or 0.1*(x1-x0).

The curve is sampled quite densely: there are 200+20 rows
Computational Costs

     ~194,800 flops

Example To read the csv file with a header in from Matlab, you need to use csvread set so that it will ignore the header row. This is accomplished by using the extra two numerical arguments for csvread to tell the function to begin reading from the 1st row, and the 0th index (csvread is 0 indexed). This is necessary to skip reading in the text header

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

◆ safeDownCast()

static FiberCompressiveForceLengthCurve* OpenSim::FiberCompressiveForceLengthCurve::safeDownCast ( OpenSim::Object obj)
inlinestatic

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

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

◆ set_curviness()

void OpenSim::FiberCompressiveForceLengthCurve::set_curviness ( const double &  value)
inline

Set the value of the curviness property.

◆ set_norm_length_at_zero_force()

void OpenSim::FiberCompressiveForceLengthCurve::set_norm_length_at_zero_force ( const double &  value)
inline

Set the value of the norm_length_at_zero_force property.

◆ set_stiffness_at_zero_length()

void OpenSim::FiberCompressiveForceLengthCurve::set_stiffness_at_zero_length ( const double &  value)
inline

Set the value of the stiffness_at_zero_length property.

◆ setNormLengthAtZeroForce()

void OpenSim::FiberCompressiveForceLengthCurve::setNormLengthAtZeroForce ( double  aNormLengthAtZeroForce)


Parameters
aNormLengthAtZeroForceSets the normalized fiber length at which the compressive element begins to engage. Normalized length is defined as length_norm = l/l0, where l is the length of the fiber, and l0 is the resting length of the fiber. This length must be greater than 0.

Cost The curve is rebuilt at a cost of ~174,100 flops

◆ setOptionalProperties()

void OpenSim::FiberCompressiveForceLengthCurve::setOptionalProperties ( double  aStiffnessAtZeroLength,
double  aCurviness 
)


Parameters
aStiffnessAtZeroLengthSets the stiffness of the compressive elastic force length spring when the fiber reaches a normalized length of 0. This stiffness must be less than -1/normLengthAtZeroForce
aCurviness
A dimensionless parameter between [0-1] that controls how the curve is drawn: 0 will create a curve that is very close to a straight line segment while a value of 1 will create a curve that smoothly fills the corner formed by the linear extrapolation of 'stiffnessAtOneNormForce' and the x axis as shown in the figure. Cost The curve is rebuilt at a cost of ~174,100 flops

◆ upd_curviness()

double& OpenSim::FiberCompressiveForceLengthCurve::upd_curviness ( )
inline

Get a writable reference to the curviness property.

◆ upd_norm_length_at_zero_force()

double& OpenSim::FiberCompressiveForceLengthCurve::upd_norm_length_at_zero_force ( )
inline

Get a writable reference to the norm_length_at_zero_force property.

◆ upd_stiffness_at_zero_length()

double& OpenSim::FiberCompressiveForceLengthCurve::upd_stiffness_at_zero_length ( )
inline

Get a writable reference to the stiffness_at_zero_length property.

OpenSim Property, Socket, Output, Input Documentation

◆ curviness

double OpenSim::FiberCompressiveForceLengthCurve::curviness

"Fiber curve bend, from linear to maximum bend (0-1)"

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

See also
get_curviness(), upd_curviness(), set_curviness()

◆ norm_length_at_zero_force

double OpenSim::FiberCompressiveForceLengthCurve::norm_length_at_zero_force

"Normalized fiber length at zero force"

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

See also
get_norm_length_at_zero_force(), upd_norm_length_at_zero_force(), set_norm_length_at_zero_force()

◆ stiffness_at_zero_length

double OpenSim::FiberCompressiveForceLengthCurve::stiffness_at_zero_length

"Fiber stiffness at zero length"

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

See also
get_stiffness_at_zero_length(), upd_stiffness_at_zero_length(), set_stiffness_at_zero_length()

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