API
4.3
For MATLAB, Python, Java, and C++ users
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This class serves as a serializable FiberCompressiveForceCosPennationCurve, which is used to ensure that the pennation angle approaches but never reaches an angle of 90 degrees.
More...
OpenSim Properties, Sockets, Outputs, Inputs | |
Properties (single-value) | |
double | engagement_angle_in_degrees |
"Engagement angle of the compressive pennation spring in degrees" More... | |
Properties (optional) | |
double | stiffness_at_perpendicular |
"Stiffness of the curve at pennation angle of 90 degrees" More... | |
double | curviness |
"Fiber curve bend, from linear to maximum bend (0-1)" More... | |
Public Member Functions | |
FiberCompressiveForceCosPennationCurve () | |
Default constructor creates an curve with the default property values, and assigns it a default name. More... | |
FiberCompressiveForceCosPennationCurve (double engagementAngleInDegrees, double stiffnessAtPerpendicular, double curviness, const std::string &muscleName) | |
Constructs a C2 continuous compressive fiber force cos pennation curve. More... | |
FiberCompressiveForceCosPennationCurve (double engagementAngleInDegrees, const std::string &muscleName) | |
Constructs a C2 continuous compressive fiber force cos pennation curve using only the mandatory property, engagmentAngleInDegrees. More... | |
double | getEngagementAngleInDegrees () const |
More... | |
double | getStiffnessAtPerpendicularInUse () const |
More... | |
double | getCurvinessInUse () const |
More... | |
bool | isFittedCurveBeingUsed () const |
More... | |
void | setEngagementAngleInDegrees (double aEngagementAngleInDegrees) |
More... | |
void | setOptionalProperties (double aStiffnessAtPerpendicular, double aCurviness) |
More... | |
double | calcValue (double cosPennationAngle) const |
Calculates the value of the curve evaluated at cosPennationAngle. More... | |
double | calcValue (const SimTK::Vector &x) const override |
Implement the generic OpenSim::Function interface. More... | |
double | calcDerivative (double cosPennationAngle, int order) const |
Calculates the derivative of the fiber compressive force pennation angle 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 cosPennationAngle) 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_engagement_angle_in_degrees () const |
Get the value of the engagement_angle_in_degrees property. More... | |
double & | upd_engagement_angle_in_degrees () |
Get a writable reference to the engagement_angle_in_degrees property. More... | |
void | set_engagement_angle_in_degrees (const double &value) |
Set the value of the engagement_angle_in_degrees property. More... | |
const double & | get_stiffness_at_perpendicular () const |
Get the value of the stiffness_at_perpendicular property. More... | |
double & | upd_stiffness_at_perpendicular () |
Get a writable reference to the stiffness_at_perpendicular property. More... | |
void | set_stiffness_at_perpendicular (const double &value) |
Set the value of the stiffness_at_perpendicular 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) |
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 FiberCompressiveForceCosPennationCurve * | safeDownCast (OpenSim::Object *obj) |
For use in MATLAB and Python to access the concrete class. More... | |
static const std::string & | getClassName () |
This returns "FiberCompressiveForceCosPennationCurve". More... | |
FiberCompressiveForceCosPennationCurve * | 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... | |
This class serves as a serializable FiberCompressiveForceCosPennationCurve, which is used to ensure that the pennation angle approaches but never reaches an angle of 90 degrees.
Preventing the fibers from achieving a pennation angle of 90 degrees is important for equilibrium muscle models which have a singularity at this value.
This curve is designed to work with the muscle model in such a way that it acts like a spring that the pennated muscle fibers contact it as the fiber rotates (circled in red). When the spring engages it will exert a force on the fiber that will prevent it from shortening further, thus preventing the pennation angle from reaching 90 degrees.
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.
OpenSim::FiberCompressiveForceCosPennationCurve::FiberCompressiveForceCosPennationCurve | ( | ) |
Default constructor creates an curve with the default property values, and assigns it a default name.
OpenSim::FiberCompressiveForceCosPennationCurve::FiberCompressiveForceCosPennationCurve | ( | double | engagementAngleInDegrees, |
double | stiffnessAtPerpendicular, | ||
double | curviness, | ||
const std::string & | muscleName | ||
) |
Constructs a C2 continuous compressive fiber force cos pennation curve.
The sole purpose of this curve is to prevent the pennation angle from reaching an angle of 90 degrees. Details to appear in Millard et al. 2012.
engagementAngleInDegrees | The pennation angle engagement angle of the fiber compressive force pennation curve. Making the spring engage too far from 90 degrees may unrealistically limit the force production capability of the muscle. An engagement angle of 80 degrees is a good place to start. |
stiffnessAtPerpendicular | This is the stiffness of the compressive elastic force length spring when the pennation angle reaches 90 degrees. Note that the units of this stiffness are (normalized force) / cos(engagmentAngleInDegrees). If the engagement angle is 80 degrees, a good stiffness to start with is -2*(1/cosd(engagementAngleInDegrees)) |
curviness | 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 'stiffnessAtPerpendicularFiber' and the x axis as shown in the figure. A good curviness parameter value to start with is 0.5. |
muscleName | The 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 "_FiberCompressiveForceCosPennationCurve" 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
0 < engagmentAngleInDegrees < 90 stiffnessAtPerpendicular < -1/engagmentAngleInDegrees 0 <= curviness <= 1
Computational Costs
~174,100 flops
Default Parameter Values
engagmentAngleInDegrees = 80
OpenSim::FiberCompressiveForceCosPennationCurve::FiberCompressiveForceCosPennationCurve | ( | double | engagementAngleInDegrees, |
const std::string & | muscleName | ||
) |
Constructs a C2 continuous compressive fiber force cos pennation curve using only the mandatory property, engagmentAngleInDegrees.
The sole purpose of this curve is to prevent the pennation angle from reaching an angle of 90 degrees. Details to appear in Millard et al. 2012.
engagementAngleInDegrees | The pennation angle engagement angle of the fiber compressive force pennation curve. Making the spring engage too far from 90 degrees may unrealistically limit the force production capability of the muscle. An engagement angle of 80 degrees is a good place to start. |
muscleName | The 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 "_FiberCompressiveForceCosPennationCurve" 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. |
Optional Parameters If the optional parameters have not yet been set, they are computed when functions getStiffnessAtPerpendicularInUse(), and getCurvinessInUse() are called. See the documentation for these functions for details
Conditions:
0 < engagmentAngleInDegrees < 90
Computational Costs
~174,100 flops
Default Parameter Values
engagmentAngleInDegrees = 80
Example:
double OpenSim::FiberCompressiveForceCosPennationCurve::calcDerivative | ( | double | cosPennationAngle, |
int | order | ||
) | const |
Calculates the derivative of the fiber compressive force pennation angle curve w.r.t.
to cosPennationAngle.
cosPennationAngle | The cosine of the fiber pennation angle |
order | the order of the derivative. Only values of 0,1 and 2 are acceptable. |
Computational Costs
x in curve domain : ~391 flops x in linear section: ~2 flops
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overridevirtual |
If possible, use the simpler overload above.
Reimplemented from OpenSim::Function.
double OpenSim::FiberCompressiveForceCosPennationCurve::calcIntegral | ( | double | cosPennationAngle | ) | const |
cosPennationAngle | The cosine of the pennation angle |
Computational Costs
x in curve domain : ~13 flops x in linear section: ~19 flops
double OpenSim::FiberCompressiveForceCosPennationCurve::calcValue | ( | double | cosPennationAngle | ) | const |
Calculates the value of the curve evaluated at cosPennationAngle.
cosPennationAngle | The cosine of the fiber pennation angle |
Computational Costs
x in curve domain : ~282 flops x in linear section: ~5 flops
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inlineoverridevirtual |
Implement the generic OpenSim::Function interface.
Reimplemented from OpenSim::Function.
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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.
void OpenSim::FiberCompressiveForceCosPennationCurve::ensureCurveUpToDate | ( | ) |
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inline |
Get the value of the curviness property.
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inline |
Get the value of the engagement_angle_in_degrees property.
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inline |
Get the value of the stiffness_at_perpendicular property.
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inlinestatic |
This returns "FiberCompressiveForceCosPennationCurve".
See getConcreteClassName() if you want the class name of the underlying concrete object instead.
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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.
Implements OpenSim::Function.
SimTK::Vec2 OpenSim::FiberCompressiveForceCosPennationCurve::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.
double OpenSim::FiberCompressiveForceCosPennationCurve::getCurvinessInUse | ( | ) | const |
If this property is empty, then a value is computed and returned. The value is computed using the following:
curviness = 0.1
double OpenSim::FiberCompressiveForceCosPennationCurve::getEngagementAngleInDegrees | ( | ) | const |
double OpenSim::FiberCompressiveForceCosPennationCurve::getStiffnessAtPerpendicularInUse | ( | ) | const |
stiffnessAtPerpendicular = -2 * 1/cosd(engagementAngleInDegrees)
where cosd is a cosine function that takes its argument in units of degrees
bool OpenSim::FiberCompressiveForceCosPennationCurve::isFittedCurveBeingUsed | ( | ) | const |
void OpenSim::FiberCompressiveForceCosPennationCurve::printMuscleCurveToCSVFile | ( | const std::string & | path | ) |
This function will generate a csv file with a name that matches the curve name (e.g.
"bicepfemoris_FiberCompressiveForceCosPennationCurve.csv"). This function is not const to permit the curve to be rebuilt if it is out of date with its properties.
path | The 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_FiberCompressiveForceCosPennationCurve.csv',1,0);
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inlinestatic |
For use in MATLAB and Python to access the concrete class.
Example: cObj = FiberCompressiveForceCosPennationCurve.safeDownCast(obj)
. This is equivalent to dynamic_cast<FiberCompressiveForceCosPennationCurve*>(obj)
in C++.
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inline |
Set the value of the curviness property.
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inline |
Set the value of the engagement_angle_in_degrees property.
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inline |
Set the value of the stiffness_at_perpendicular property.
void OpenSim::FiberCompressiveForceCosPennationCurve::setEngagementAngleInDegrees | ( | double | aEngagementAngleInDegrees | ) |
aEngagementAngleInDegrees | Sets the pennation angle engagement angle of the fiber compressive force pennation curve. Cost The curve is rebuilt at a cost of ~174,100 flops |
void OpenSim::FiberCompressiveForceCosPennationCurve::setOptionalProperties | ( | double | aStiffnessAtPerpendicular, |
double | aCurviness | ||
) |
aStiffnessAtPerpendicular | This is the stiffness of the compressive elastic force length spring when the pennation angle reaches 90 degrees. |
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
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inline |
Get a writable reference to the curviness property.
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inline |
Get a writable reference to the engagement_angle_in_degrees property.
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inline |
Get a writable reference to the stiffness_at_perpendicular property.
double OpenSim::FiberCompressiveForceCosPennationCurve::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.
double OpenSim::FiberCompressiveForceCosPennationCurve::engagement_angle_in_degrees |
"Engagement angle of the compressive pennation spring in degrees"
This property appears in XML files under the tag <engagement_angle_in_degrees>. This property was generated with the OpenSim_DECLARE_PROPERTY macro; see Property to learn about the property system.
double OpenSim::FiberCompressiveForceCosPennationCurve::stiffness_at_perpendicular |
"Stiffness of the curve at pennation angle of 90 degrees"
This property appears in XML files under the tag <stiffness_at_perpendicular>. This property was generated with the OpenSim_DECLARE_OPTIONAL_PROPERTY macro; see Property to learn about the property system.