OpenSim
OpenSim 3.2
|
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...
#include <FiberCompressiveForceCosPennationCurve.h>
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 manditory property, engagmentAngleInDegrees. More... | |
double | getEngagementAngleInDegrees () const |
double | getStiffnessAtPerpendicularInUse () const |
double | getCurvinessInUse () const |
bool | isFittedCurveBeingUsed () const |
void | setEngagementAngleInDegrees (double aEngagementAngleInDegrees) |
void | setOptionalProperties (double aStiffnessAtPerpendicular, double aCurviness) |
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 | calcIntegral (double cosPennationAngle) const |
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 declarations | |
These are the serializable properties associated with this class. | |
OpenSim_DECLARE_PROPERTY (engagement_angle_in_degrees, double,"Engagement angle of the compressive pennation spring in degrees") | |
OpenSim_DECLARE_OPTIONAL_PROPERTY (stiffness_at_perpendicular, double,"Stiffness of the curve at pennation angle of 90 degrees") | |
OpenSim_DECLARE_OPTIONAL_PROPERTY (curviness, double,"Fiber curve bend, from linear to maximum bend (0-1)") | |
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 double | calcDerivative (const std::vector< int > &derivComponents, const SimTK::Vector &x) const |
Calculate a partial derivative of this function at a particular point. More... | |
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... | |
virtual Object * | clone () const =0 |
Create a new heap-allocated copy of the concrete object to which this Object refers. More... | |
virtual const std::string & | getConcreteClassName () const =0 |
Returns the class name of the concrete Object-derived class of the actual object referenced by this Object, as a string. More... | |
virtual const VisibleObject * | getDisplayer () const |
Methods to support making the object displayable in the GUI or Visualizer Implemented only in few objects. More... | |
virtual VisibleObject * | updDisplayer () |
get Non const pointer to VisibleObject 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, call this method in your constructor if needed. 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... | |
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... | |
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... | |
virtual void | updateXMLNode (SimTK::Xml::Element &parent) |
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... | |
void | setAllPropertiesUseDefault (bool aUseDefault) |
bool | print (const std::string &fileName) |
Write this Object into an XML file of the given name; conventionally the suffix to use is ".osim". More... | |
std::string | dump (bool dumpName=false) |
dump the XML representation of this Object into an std::string and return it. More... | |
void | clearObjectIsUpToDateWithProperties () |
For testing or debugging purposes, manually clear the "object is up to
date with respect to properties" flag. 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 |
Additional Inherited Members | |
Static Public Member Functions inherited from OpenSim::Function | |
static Function * | makeFunctionOfType (Function *aFunction, const std::string &aNewTypeName) |
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 Attributes inherited from OpenSim::Function | |
SimTK::Function * | _function |
Related Functions inherited from OpenSim::Object | |
#define | OpenSim_DECLARE_CONCRETE_OBJECT(ConcreteClass, SuperClass) |
Macro to be included as the first line of the class declaration for any non-templatized, concrete class that derives from OpenSim::Object. More... | |
#define | OpenSim_DECLARE_ABSTRACT_OBJECT(ConcreteClass, SuperClass) |
Macro to be included as the first line of the class declaration for any still-abstract class that derives from OpenSim::Object. More... | |
#define | OpenSim_DECLARE_CONCRETE_OBJECT_T(ConcreteClass, TArg, SuperClass) |
Macro to be included as the first line of the class declaration for any templatized, concrete class that derives from OpenSim::Object, like Set<T>. More... | |
#define | OpenSim_DECLARE_ABSTRACT_OBJECT_T(ConcreteClass, TArg, SuperClass) |
Macro to be included as the first line of the class declaration for any templatized, still-abstract class that derives from OpenSim::Object. 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 achivieving 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 (circuled 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
Example:
OpenSim::FiberCompressiveForceCosPennationCurve::FiberCompressiveForceCosPennationCurve | ( | double | engagementAngleInDegrees, |
const std::string & | muscleName | ||
) |
Constructs a C2 continuous compressive fiber force cos pennation curve using only the manditory 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
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
|
inlineoverridevirtual |
Implement the generic OpenSim::Function interface.
Reimplemented from OpenSim::Function.
void OpenSim::FiberCompressiveForceCosPennationCurve::ensureCurveUpToDate | ( | ) |
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 |
OpenSim::FiberCompressiveForceCosPennationCurve::OpenSim_DECLARE_OPTIONAL_PROPERTY | ( | stiffness_at_perpendicular | , |
double | , | ||
"Stiffness of the curve at pennation angle of 90 degrees" | |||
) |
OpenSim::FiberCompressiveForceCosPennationCurve::OpenSim_DECLARE_OPTIONAL_PROPERTY | ( | curviness | , |
double | , | ||
"Fiber curve | bend, | ||
from linear to maximum bend(0-1)" | |||
) |
OpenSim::FiberCompressiveForceCosPennationCurve::OpenSim_DECLARE_PROPERTY | ( | engagement_angle_in_degrees | , |
double | , | ||
"Engagement angle of the compressive pennation spring in degrees" | |||
) |
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);
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