DerivativeTrajectory< T > Class Template Reference

Detailed Description

template<typename T>
class drake::trajectories::DerivativeTrajectory< T >

Trajectory objects provide derivatives by implementing DoEvalDerivative and DoMakeDerivative.

DoEvalDerivative evaluates the derivative value at a point in time. DoMakeDerivative returns a new Trajectory object which represents the derivative.

In some cases, it is easy to implement DoEvalDerivative, but difficult or inefficient to implement DoMakeDerivative natively. And it may be just as efficient to use DoEvalDerivative even in repeated evaluations of the derivative. The DerivativeTrajectory class helps with this case – given a nominal Trajectory, it provides a Trajectory interface that calls nominal.EvalDerivative() to implement Trajectory::value().

Template Parameters

T	The scalar type, which must be one of the default scalars.

#include <drake/common/trajectories/derivative_trajectory.h>

Public Member Functions
	DerivativeTrajectory (const Trajectory< T > &nominal, int derivative_order=1)
	Creates a DerivativeTrajectory representing the derivative_order derivatives of nominal. More...
	~DerivativeTrajectory () final
std::unique_ptr< Trajectory< T > >	Clone () const final
MatrixX< T >	value (const T &t) const final
	Evaluates the trajectory at the given time t. More...
Eigen::Index	rows () const final
Eigen::Index	cols () const final
T	start_time () const final
T	end_time () const final
Implements CopyConstructible, CopyAssignable, MoveConstructible, MoveAssignable
	DerivativeTrajectory (const DerivativeTrajectory &)=default
DerivativeTrajectory &	operator= (const DerivativeTrajectory &)=default
	DerivativeTrajectory (DerivativeTrajectory &&)=default
DerivativeTrajectory &	operator= (DerivativeTrajectory &&)=default
Public Member Functions inherited from Trajectory< T >
virtual	~Trajectory ()=default
MatrixX< T >	vector_values (const std::vector< T > &t) const
	If cols()==1, then evaluates the trajectory at each time t, and returns the results as a Matrix with the ith column corresponding to the ith time. More...
MatrixX< T >	vector_values (const Eigen::Ref< const VectorX< T >> &t) const
	If cols()==1, then evaluates the trajectory at each time t, and returns the results as a Matrix with the ith column corresponding to the ith time. More...
bool	has_derivative () const
	Returns true iff the Trajectory provides and implementation for EvalDerivative() and MakeDerivative(). More...
MatrixX< T >	EvalDerivative (const T &t, int derivative_order=1) const
	Evaluates the derivative of this at the given time t. More...
std::unique_ptr< Trajectory< T > >	MakeDerivative (int derivative_order=1) const
	Takes the derivative of this Trajectory. More...

Additional Inherited Members
Protected Member Functions inherited from Trajectory< T >
	Trajectory ()=default
	Trajectory (const Trajectory &)=default
Trajectory &	operator= (const Trajectory &)=default
	Trajectory (Trajectory &&)=default
Trajectory &	operator= (Trajectory &&)=default

Constructor & Destructor Documentation

DerivativeTrajectory() [1/3]

DerivativeTrajectory ( const DerivativeTrajectory< T > &  )

default

DerivativeTrajectory() [2/3]

DerivativeTrajectory ( DerivativeTrajectory< T > &&  )

default

DerivativeTrajectory() [3/3]

DerivativeTrajectory ( const Trajectory< T > &  nominal, int  derivative_order = 1  )

explicit

Creates a DerivativeTrajectory representing the derivative_order derivatives of nominal.

This constructor makes a Clone() of nominal and does not hold on to the reference.

Exceptions

std::exception	if !nominal.has_derivative().
std::exception	if derivative_order < 0.

~DerivativeTrajectory()

~DerivativeTrajectory ( )

final

Member Function Documentation

Clone()

std::unique_ptr<Trajectory<T> > Clone ( ) const

finalvirtual

Returns

A deep copy of this Trajectory.

Implements Trajectory< T >.

cols()

Eigen::Index cols ( ) const

finalvirtual

Returns

The number of columns in the matrix returned by value().

Implements Trajectory< T >.

end_time()

T end_time ( ) const

finalvirtual

Implements Trajectory< T >.

operator=() [1/2]

DerivativeTrajectory& operator= ( DerivativeTrajectory< T > &&  )

default

operator=() [2/2]

DerivativeTrajectory& operator= ( const DerivativeTrajectory< T > &  )

default

rows()

Eigen::Index rows ( ) const

finalvirtual

Returns

The number of rows in the matrix returned by value().

Implements Trajectory< T >.

start_time()

T start_time ( ) const

finalvirtual

Implements Trajectory< T >.

value()

MatrixX<T> value ( const T &  t ) const

finalvirtual

Evaluates the trajectory at the given time t.

Parameters

t	The time at which to evaluate the trajectory.

Returns

The matrix of evaluated values.

Implements Trajectory< T >.

---

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

• drake/common/trajectories/derivative_trajectory.h