SimTK::Measure_< T >::Extreme Class Reference

This Measure tracks extreme values attained by the elements of its source operand since the last initialize() call or explicit call to setValue(). More...

#include <Measure.h>

Inheritance diagram for SimTK::Measure_< T >::Extreme:

List of all members.

Classes
class	Implementation
Public Member Functions
	SimTK_MEASURE_HANDLE_PREAMBLE (Extreme, Measure_< T >)
	Extreme (Subsystem &sub, const Measure_< T > &operand, Operation op=MaxAbs)
	Default behavior for the Extreme measure is to find the operand's value that is of maximum absolute value.
Extreme &	setOperation (Operation op)
	Set the operation to be performed.
Operation	getOperation () const
	Return the operation currently being performed by this measure.
Real	getTimeOfExtremeValue (const State &state) const
	Return the time at which the reported extreme value first occurred.
void	setValue (State &s, const T &value) const
const Measure_< T > &	getOperandMeasure () const
Extreme &	setOperandMeasure (const Measure_< T > &s)
	SimTK_MEASURE_HANDLE_POSTSCRIPT (Extreme, Measure_< T >)

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Detailed Description

template<class T>
class SimTK::Measure_< T >::Extreme

This Measure tracks extreme values attained by the elements of its source operand since the last initialize() call or explicit call to setValue().

The extreme is either minimum or maximum and may be determined by the actual or absolute value of the operand. In any case the value of the Extreme measure is the actual extreme value of the operand, not its absolute value.

The template type T must be the same as the template type of the operand measure. If T is a Vec or Vector type, each element is treated separately.

Normally Extreme is not used directly; it is the common implementation underlying the Minimum, Maximum, MinAbs, and MaxAbs measures.

Information available from this Measure:

• the current extreme value (at the source's stage)
• the value at the start of the current step (Time stage)
• time of last change
• the DiscreteVariableIndex holding the previous value
• the CacheEntryIndex designated for the current/next value
• a reference to the source Measure

The time derivative fdot of f(t)=min_t0_t(s(t')) where s is the source measure and t0 <= t' <= t is

     fdot(t) = s(t) < f(ti) && sdot(t) < 0 ? sdot(t) : 0

where ti is the time at the start of the current step.

At the start of a continuous interval, the updated value (if any) replaces the stored value.

Extreme isolation (not implemented yet)

If the time derivative of the source operand is available, the measure will arrange to ensure precise isolation of the minimum values by defining a triggered event that watches for negative-to-positive sign changes of the derivative. Then if you output reporting data upon the occurrence of triggered events (as well as your regularly scheduled output) your data will include the precise minimum (to within a specifiable isolation time window).

Additional information available in this case:

• the EventId of the extreme-trapping event if there is one
• the time derivative of the Extreme measure

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Constructor & Destructor Documentation

template<class T>

SimTK::Measure_< T >::Extreme::Extreme	(	Subsystem &	sub,
		const Measure_< T > &	operand,
		Operation	op = MaxAbs
	)		[inline]

Default behavior for the Extreme measure is to find the operand's value that is of maximum absolute value.

You can change that to minimum and/or actual value.

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Member Function Documentation

template<class T>

SimTK::Measure_< T >::Extreme::SimTK_MEASURE_HANDLE_PREAMBLE	(	Extreme	,
		Measure_< T >
	)

template<class T>

Extreme& SimTK::Measure_< T >::Extreme::setOperation

(

Operation

op

)

[inline]

Set the operation to be performed.

The default operation is MaxAbs.

template<class T>

Operation SimTK::Measure_< T >::Extreme::getOperation

(

)

const [inline]

Return the operation currently being performed by this measure.

template<class T>

Real SimTK::Measure_< T >::Extreme::getTimeOfExtremeValue

(

const State &

state

)

const [inline]

Return the time at which the reported extreme value first occurred.

This is the current time if the operand is at its extreme value now, otherwise it is the time that the extreme value first occurred during a time stepping study. The state must be realized to the level required to evaluate the operand measure.

template<class T>

void SimTK::Measure_< T >::Extreme::setValue	(	State &	s,
		const T &	value
	)		const [inline]

template<class T>

const Measure_<T>& SimTK::Measure_< T >::Extreme::getOperandMeasure

(

)

const [inline]

template<class T>

Extreme& SimTK::Measure_< T >::Extreme::setOperandMeasure

(

const Measure_< T > &

s

)

[inline]

template<class T>

SimTK::Measure_< T >::Extreme::SimTK_MEASURE_HANDLE_POSTSCRIPT	(	Extreme	,
		Measure_< T >
	)

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

• Measure.h