EquilibriumAxialMuscle (Artisynth API documentation)

java.lang.Object
- artisynth.core.materials.MaterialBase
- - artisynth.core.materials.AxialMaterial
  - - artisynth.core.materials.AxialMuscleMaterialBase
    - - artisynth.core.materials.EquilibriumAxialMuscle

All Implemented Interfaces:

HasMaterialState, HasNumericState, PostScannable, ScalableUnits, java.lang.Cloneable, CompositeProperty, HasProperties, Clonable, Scannable

Direct Known Subclasses:

Millard2012AxialMuscle, Thelen2003AxialMuscle
```
public abstract class EquilibriumAxialMuscle
extends AxialMuscleMaterialBase
implements HasNumericState
```
Base class for point-to-point muscle materials that implement a pennated muscle and tendon in series, and which solve for the muscle length at each time step to ensure that the muscle and tendon forces are equal.

Field Summary

Fields
Modifier and Type	Field and Description
`boolean`	`debug`
`static boolean`	`DEFAULT_COMPUTE_LMDOT_FROM_LDOT`
`static double`	`DEFAULT_FIBRE_DAMPING`
`static boolean`	`DEFAULT_IGNORE_FORCE_VELOCITY`
`static double`	`DEFAULT_MAX_CONTRACTION_VELOCITY`
`static double`	`DEFAULT_MAX_ISO_FORCE`
`static double`	`DEFAULT_MUSCLE_LENGTH`
`static double`	`DEFAULT_OPT_FIBRE_LENGTH`
`static double`	`DEFAULT_OPT_PENNATION_ANGLE`
`static boolean`	`DEFAULT_RIGID_TENDON`
`static double`	`DEFAULT_TENDON_SLACK_LENGTH`
`static PropertyList`	`myProps`
`static boolean`	`useFindLm`
`static boolean`	`useNewtonSolver`
`boolean`	`vmFromTendon`

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`void`	`advanceState(double t0, double t1)` If `HasNumericState.requiresAdvance()` and `HasNumericState.hasState()` both return `true`, then this method is called each time step by the system integrator to update this component's state.
`double`	`computeDFdl(double l, double ldot, double l0, double excitation)` Computes and returns the derivative of the axial spring tension with respect to the length.
`double`	`computeDFdldot(double l, double ldot, double l0, double excitation)` Computes and returns the derivative of the axial spring tension with respect to the length time derivative.
`double`	`computeF(double l, double ldot, double l0, double excitation)` Computes and returns the axial spring tension, as a function of length, length time derivative, rest length, and excitation.
`double`	`computeG(DoubleHolder dG, double l, double lm, double vm, double a, double h)`
`double`	`computeLmWithConstantVm(double l, double vm, double a)`
`double`	`computeLmWithVmFromLm(double l, double ldot, double a, double h)`
`double`	`computePassiveF(double l, double ldot, double l0, double excitation)`
`double`	`computeVmFromLdot(double ldot)`
`double`	`fibreToMuscleLength(double lf)` Computes the muscle length corresponding to a given fibre length.
`PropertyList`	`getAllPropertyInfo()` Returns a list giving static information about all properties exported by this object.
`boolean`	`getComputeLmDotFromLDot()`
`double`	`getFibreDamping()`
`boolean`	`getIgnoreForceVelocity()`
`boolean`	`getIgnoreTendonCompliance()` Deprecated. Use `hasRigidTendon()` instead.
`double`	`getLength()`
`double`	`getMaxContractionVelocity()`
`double`	`getMaxIsoForce()`
`double`	`getMuscleLength()`
`double`	`getOptFibreLength()`
`double`	`getOptPennationAngle()`
`void`	`getState(DataBuffer data)` Saves state information for this component by adding data to the supplied DataBuffer.
`int`	`getStateVersion()` Returns a version number for this component's state.
`double`	`getTendonLength()`
`double`	`getTendonSlackLength()`
`boolean`	`hasRigidTendon()` Queries whether the tendon for this muscle material is rigid.
`boolean`	`hasState()` Returns `true` if this component currently holds state.
`double`	`initializeLmPrevFromLdot(double l, double ldot, double a)`
`boolean`	`isDFdldotZero()` Returns true if computeDFdldot() always returns zero.
`boolean`	`requiresAdvance()` Returns `true` if the state of this component must be updated each time step using `HasNumericState.advanceState(double, double)`.
`void`	`scaleDistance(double s)` Scales all distance coordinates.
`void`	`scaleMass(double s)` Scales all mass units.
`void`	`setComputeLmDotFromLDot(boolean enable)`
`void`	`setFibreDamping(double d)`
`void`	`setIgnoreForceVelocity(boolean enable)`
`void`	`setIgnoreTendonCompliance(boolean enable)` Deprecated. Use `setRigidTendon(boolean)` instead.
`void`	`setLength(double l)`
`void`	`setMaxContractionVelocity(double maxv)`
`void`	`setMaxIsoForce(double fmax)`
`void`	`setMuscleLength(double l)`
`void`	`setOptFibreLength(double l)`
`void`	`setOptPennationAngle(double ang)`
`void`	`setRigidTendon(boolean enable)` Set whether the tendon for this muscle material is rigid.
`void`	`setState(DataBuffer data)` Restores the state for this component by reading from the supplied data buffer, starting at the current buffer offsets.
`void`	`setTendonSlackLength(double l)`
`void`	`writeActiveForceLengthCurve(java.lang.String fileName, double x0, double x1, int npnts, java.lang.String fmtStr)`
`void`	`writeForceVelocityCurve(java.lang.String fileName, double a, double x0, double x1, int npnts, java.lang.String fmtStr)`
`void`	`writePassiveForceLengthCurve(java.lang.String fileName, double x0, double x1, int npnts, java.lang.String fmtStr)`
`void`	`writeTendonForceLengthCurve(java.lang.String fileName, double x0, double x1, int npnts, java.lang.String fmtStr)`

Methods inherited from class artisynth.core.materials.AxialMaterial
clone, equals, equals, getSubClasses

Methods inherited from class artisynth.core.materials.MaterialBase
advanceState, createStateObject, getProperty, getPropertyHost, getPropertyInfo, hasProperty, hasSymmetricTangent, isWritable, postscan, scan, setPropertyHost, setPropertyInfo, symmetryOrStateChanged, updateMaterial, write, writeItems

Methods inherited from class java.lang.Object
getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface artisynth.core.modelbase.HasNumericState
getAuxVarDerivative, getAuxVarState, numAuxVars, setAuxVarState

- Field Detail
  - useNewtonSolver
```
public static boolean useNewtonSolver
```
  - useFindLm
```
public static boolean useFindLm
```
  - vmFromTendon
```
public boolean vmFromTendon
```
  - DEFAULT_MAX_ISO_FORCE
```
public static double DEFAULT_MAX_ISO_FORCE
```
  - DEFAULT_OPT_FIBRE_LENGTH
```
public static double DEFAULT_OPT_FIBRE_LENGTH
```
  - DEFAULT_TENDON_SLACK_LENGTH
```
public static double DEFAULT_TENDON_SLACK_LENGTH
```
  - DEFAULT_OPT_PENNATION_ANGLE
```
public static double DEFAULT_OPT_PENNATION_ANGLE
```
  - DEFAULT_MAX_CONTRACTION_VELOCITY
```
public static double DEFAULT_MAX_CONTRACTION_VELOCITY
```
  - DEFAULT_FIBRE_DAMPING
```
public static double DEFAULT_FIBRE_DAMPING
```
  - DEFAULT_RIGID_TENDON
```
public static boolean DEFAULT_RIGID_TENDON
```
  - DEFAULT_IGNORE_FORCE_VELOCITY
```
public static boolean DEFAULT_IGNORE_FORCE_VELOCITY
```
  - DEFAULT_COMPUTE_LMDOT_FROM_LDOT
```
public static boolean DEFAULT_COMPUTE_LMDOT_FROM_LDOT
```
  - DEFAULT_MUSCLE_LENGTH
```
public static double DEFAULT_MUSCLE_LENGTH
```
  - myProps
```
public static PropertyList myProps
```
  - debug
```
public boolean debug
```
- Method Detail
  - getStateVersion
```
public int getStateVersion()
```
    Description copied from interface: HasNumericState
    
    Returns a version number for this component's state. When the version number changes, any previously saved state should be considered no longer compatible. The default implementation of this method always returns 0, indicating that state compatibility never changes.
    
    Specified by:
    
    getStateVersion in interface HasNumericState
  - getAllPropertyInfo
```
public PropertyList getAllPropertyInfo()
```
    Description copied from interface: HasProperties
    
    Returns a list giving static information about all properties exported by this object.
    
    Specified by:
    
    getAllPropertyInfo in interface HasProperties
    
    Overrides:
    
    getAllPropertyInfo in class MaterialBase
    
    Returns:
    
    static information for all exported properties
  - getMaxIsoForce
```
public double getMaxIsoForce()
```
  - setMaxIsoForce
```
public void setMaxIsoForce(double fmax)
```
  - getOptFibreLength
```
public double getOptFibreLength()
```
  - setOptFibreLength
```
public void setOptFibreLength(double l)
```
  - getTendonSlackLength
```
public double getTendonSlackLength()
```
  - setTendonSlackLength
```
public void setTendonSlackLength(double l)
```
  - getOptPennationAngle
```
public double getOptPennationAngle()
```
  - setOptPennationAngle
```
public void setOptPennationAngle(double ang)
```
  - getMaxContractionVelocity
```
public double getMaxContractionVelocity()
```
  - setMaxContractionVelocity
```
public void setMaxContractionVelocity(double maxv)
```
  - getFibreDamping
```
public double getFibreDamping()
```
  - setFibreDamping
```
public void setFibreDamping(double d)
```
  - getIgnoreTendonCompliance
```
public boolean getIgnoreTendonCompliance()
```
    Deprecated. Use hasRigidTendon() instead.
  - setIgnoreTendonCompliance
```
public void setIgnoreTendonCompliance(boolean enable)
```
    Deprecated. Use setRigidTendon(boolean) instead.
  - hasRigidTendon
```
public boolean hasRigidTendon()
```
    Queries whether the tendon for this muscle material is rigid.
    
    Returns:
    
    true if the tendon is rigid
  - setRigidTendon
```
public void setRigidTendon(boolean enable)
```
    Set whether the tendon for this muscle material is rigid.
    
    Parameters:
    
    enable - if true, sets the tendon rigid
  - getIgnoreForceVelocity
```
public boolean getIgnoreForceVelocity()
```
  - setIgnoreForceVelocity
```
public void setIgnoreForceVelocity(boolean enable)
```
  - getComputeLmDotFromLDot
```
public boolean getComputeLmDotFromLDot()
```
  - setComputeLmDotFromLDot
```
public void setComputeLmDotFromLDot(boolean enable)
```
  - getTendonLength
```
public double getTendonLength()
```
  - getLength
```
public double getLength()
```
  - setLength
```
public void setLength(double l)
```
  - getMuscleLength
```
public double getMuscleLength()
```
  - setMuscleLength
```
public void setMuscleLength(double l)
```
  - fibreToMuscleLength
```
public double fibreToMuscleLength(double lf)
```
    Computes the muscle length corresponding to a given fibre length. If the fibre length is less that the muscle height, returns 0.
    
    Parameters:
    
    lf - fibre length
    
    Returns:
    
    corresponding muscle length
  - computeF
```
public double computeF(double l,
                       double ldot,
                       double l0,
                       double excitation)
```
    Computes and returns the axial spring tension, as a function of length, length time derivative, rest length, and excitation.
    
    Specified by:
    
    computeF in class AxialMaterial
    
    Parameters:
    
    l - spring length
    
    ldot - spring length time derivative
    
    l0 - spring rest length
    
    excitation - excitation value (varying from 0 to 1)
    
    Returns:
    
    spring tension
  - computePassiveF
```
public double computePassiveF(double l,
                              double ldot,
                              double l0,
                              double excitation)
```
  - computeVmFromLdot
```
public double computeVmFromLdot(double ldot)
```
  - initializeLmPrevFromLdot
```
public double initializeLmPrevFromLdot(double l,
                                       double ldot,
                                       double a)
```
  - computeLmWithConstantVm
```
public double computeLmWithConstantVm(double l,
                                      double vm,
                                      double a)
```
  - computeLmWithVmFromLm
```
public double computeLmWithVmFromLm(double l,
                                    double ldot,
                                    double a,
                                    double h)
```
  - computeG
```
public double computeG(DoubleHolder dG,
                       double l,
                       double lm,
                       double vm,
                       double a,
                       double h)
```
  - computeDFdl
```
public double computeDFdl(double l,
                          double ldot,
                          double l0,
                          double excitation)
```
    Computes and returns the derivative of the axial spring tension with respect to the length.
    
    Specified by:
    
    computeDFdl in class AxialMaterial
    
    Parameters:
    
    l - spring length
    
    ldot - spring length time derivative
    
    l0 - spring rest length
    
    excitation - excitation value (varying from 0 to 1)
    
    Returns:
    
    tension derivative with respect to length
  - computeDFdldot
```
public double computeDFdldot(double l,
                             double ldot,
                             double l0,
                             double excitation)
```
    Computes and returns the derivative of the axial spring tension with respect to the length time derivative.
    
    Specified by:
    
    computeDFdldot in class AxialMaterial
    
    Parameters:
    
    l - spring length
    
    ldot - spring length time derivative
    
    l0 - spring rest length
    
    excitation - excitation value (varying from 0 to 1)
    
    Returns:
    
    tension derivative with respect to length time derivative
  - isDFdldotZero
```
public boolean isDFdldotZero()
```
    Returns true if computeDFdldot() always returns zero. For a linear spring, this simply means the damping is zero. When dFdldot is always 0, then stiffness matrix will be symmetric.
    
    Specified by:
    
    isDFdldotZero in class AxialMaterial
  - hasState
```
public boolean hasState()
```
    Description copied from interface: HasNumericState
    
    Returns true if this component currently holds state. This allows the presence of state to depend on the component's configuration.
    
    Specified by:
    
    hasState in interface HasMaterialState
    
    Specified by:
    
    hasState in interface HasNumericState
    
    Overrides:
    
    hasState in class MaterialBase
    
    Returns:
    
    true if this component holds state
  - setState
```
public void setState(DataBuffer data)
```
    Description copied from interface: HasNumericState
    
    Restores the state for this component by reading from the supplied data buffer, starting at the current buffer offsets.
    
    Specified by:
    
    setState in interface HasNumericState
    
    Parameters:
    
    data - buffer containing the state information
  - getState
```
public void getState(DataBuffer data)
```
    Description copied from interface: HasNumericState
    
    Saves state information for this component by adding data to the supplied DataBuffer. Existing data in the buffer should not be disturbed.
    
    Specified by:
    
    getState in interface HasNumericState
    
    Parameters:
    
    data - buffer for storing the state values.
  - advanceState
```
public void advanceState(double t0,
                         double t1)
```
    Description copied from interface: HasNumericState
    
    If HasNumericState.requiresAdvance() and HasNumericState.hasState() both return true, then this method is called each time step by the system integrator to update this component's state. For single step integrators, the method is called once at the start of the integration, with t0 and t1 set to the step's start and end times. For multi-step integrators (such as Runge Kutta), the method is called for each sub-step, with t0 and t1 set to the sub-step's time bounds. Multi-step integrators will also use HasNumericState.getState(maspack.util.DataBuffer) and HasNumericState.setState(maspack.util.DataBuffer) to save and restore state as required.
    
    Specified by:
    
    advanceState in interface HasNumericState
    
    Parameters:
    
    t0 - beginning time associated with the time step or sub-step
    
    t1 - end time associated with the time step or sub-step
  - requiresAdvance
```
public boolean requiresAdvance()
```
    Returns true if the state of this component must be updated each time step using HasNumericState.advanceState(double, double).
    
    Specified by:
    
    requiresAdvance in interface HasNumericState
    
    Returns:
    
    true if advanceState must be called
  - writeActiveForceLengthCurve
```
public void writeActiveForceLengthCurve(java.lang.String fileName,
                                        double x0,
                                        double x1,
                                        int npnts,
                                        java.lang.String fmtStr)
                                 throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - writePassiveForceLengthCurve
```
public void writePassiveForceLengthCurve(java.lang.String fileName,
                                         double x0,
                                         double x1,
                                         int npnts,
                                         java.lang.String fmtStr)
                                  throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - writeTendonForceLengthCurve
```
public void writeTendonForceLengthCurve(java.lang.String fileName,
                                        double x0,
                                        double x1,
                                        int npnts,
                                        java.lang.String fmtStr)
                                 throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - writeForceVelocityCurve
```
public void writeForceVelocityCurve(java.lang.String fileName,
                                    double a,
                                    double x0,
                                    double x1,
                                    int npnts,
                                    java.lang.String fmtStr)
                             throws java.io.IOException
```
    Throws:
    
    java.io.IOException
  - scaleDistance
```
public void scaleDistance(double s)
```
    Description copied from interface: ScalableUnits
    
    Scales all distance coordinates.
    
    Specified by:
    
    scaleDistance in interface ScalableUnits
    
    Overrides:
    
    scaleDistance in class MaterialBase
    
    Parameters:
    
    s - scaling factor
  - scaleMass
```
public void scaleMass(double s)
```
    Description copied from interface: ScalableUnits
    
    Scales all mass units.
    
    Specified by:
    
    scaleMass in interface ScalableUnits
    
    Overrides:
    
    scaleMass in class MaterialBase
    
    Parameters:
    
    s - scaling factor

Class EquilibriumAxialMuscle

Field Summary

Method Summary

Methods inherited from class artisynth.core.materials.AxialMaterial

Methods inherited from class artisynth.core.materials.MaterialBase

Methods inherited from class java.lang.Object

Methods inherited from interface artisynth.core.modelbase.HasNumericState

Field Detail

useNewtonSolver

useFindLm

vmFromTendon

DEFAULT_MAX_ISO_FORCE

DEFAULT_OPT_FIBRE_LENGTH

DEFAULT_TENDON_SLACK_LENGTH

DEFAULT_OPT_PENNATION_ANGLE

DEFAULT_MAX_CONTRACTION_VELOCITY

DEFAULT_FIBRE_DAMPING

DEFAULT_RIGID_TENDON

DEFAULT_IGNORE_FORCE_VELOCITY

DEFAULT_COMPUTE_LMDOT_FROM_LDOT

DEFAULT_MUSCLE_LENGTH

myProps

debug

Method Detail

getStateVersion

getAllPropertyInfo

getMaxIsoForce

setMaxIsoForce

getOptFibreLength

setOptFibreLength

getTendonSlackLength

setTendonSlackLength

getOptPennationAngle

setOptPennationAngle

getMaxContractionVelocity

setMaxContractionVelocity

getFibreDamping

setFibreDamping

getIgnoreTendonCompliance

setIgnoreTendonCompliance

hasRigidTendon

setRigidTendon

getIgnoreForceVelocity

setIgnoreForceVelocity

getComputeLmDotFromLDot

setComputeLmDotFromLDot

getTendonLength

getLength

setLength

getMuscleLength

setMuscleLength

fibreToMuscleLength

computeF

computePassiveF

computeVmFromLdot

initializeLmPrevFromLdot

computeLmWithConstantVm

computeLmWithVmFromLm

computeG

computeDFdl

computeDFdldot

isDFdldotZero

hasState

setState

getState

advanceState

requiresAdvance

writeActiveForceLengthCurve

writePassiveForceLengthCurve

writeTendonForceLengthCurve

writeForceVelocityCurve

scaleDistance

scaleMass