ls::systems::TransferFunction Class Reference

Inheritance diagram for ls::systems::TransferFunction:

Collaboration diagram for ls::systems::TransferFunction:

Public Member Functions
	TransferFunction ()
	Default constructor.
	TransferFunction (const TransferFunction &other)
	Copy constructor. More...
	TransferFunction (const Eigen::MatrixXd &num, const Eigen::MatrixXd &den)
	Constructs a transfer function from a vector of numerator and denominator coefficients. More...
Eigen::MatrixXd	getNum () const
	Gets numerator coefficients. More...
void	setNum (const Eigen::MatrixXd &num)
	Sets numerator coefficients. More...
long	getNumDegree () const
Eigen::MatrixXd	getDen () const
	Gets denominator coefficients. More...
void	setDen (const Eigen::MatrixXd &den)
	Set denominator coefficients. More...
long	getDenDegree () const
void	normalizeInPlace ()
	Normalizes transfer function in place.
TransferFunction	normalized () const
	Creates normalized transfer function. More...
StateSpace	toStateSpace () const
	Converts transfer function to state space object. More...
StateSpace	toDiscreteStateSpace (double dt) const
	Converts transfer function to discrete-time state space object. More...
StateSpace	toDiscreteStateSpace (double dt, double alpha) const
	Convert transfer function to discrete-time state space object. More...
	TransferFunction (const GiNaC::ex &tf, const GiNaC::ex &symbol)
	Constructs a transfer function from the given symbolic expression. More...
GiNaC::ex	getNumExpression (const GiNaC::ex &symbol) const
	Generates a symbolic expression of the numerator polynomial. More...
GiNaC::ex	getDenExpression (const GiNaC::ex &symbol) const
	Generates a symbolic expression of the denominator polynomial. More...
GiNaC::ex	getExpression (const GiNaC::ex &symbol) const
	Generates a symbolic expression of the transfer function. More...
void	copyFromExpression (const GiNaC::ex &tf, const GiNaC::ex &symbol)
	Copies transfer function coefficients from the given symbolic expression. More...

Constructor & Destructor Documentation

TransferFunction() [1/3]

ls::systems::TransferFunction::TransferFunction

(

const TransferFunction &

other

)

Copy constructor.

Parameters

other

Transfer function to copy.

TransferFunction() [2/3]

ls::systems::TransferFunction::TransferFunction ( const Eigen::MatrixXd &  num, const Eigen::MatrixXd &  den  )

inline

Constructs a transfer function from a vector of numerator and denominator coefficients.

Note

Coefficients are in descending order (starting with the monomial with highest power).

Parameters

num	Numerator coefficients.
den	Denominator coefficients.

TransferFunction() [3/3]

ls::systems::TransferFunction::TransferFunction	(	const GiNaC::ex &	tf,
		const GiNaC::ex &	symbol
	)

Constructs a transfer function from the given symbolic expression.

Parameters

tf	Transfer function expression.
symbol	Symbol used for the independent variable.

Member Function Documentation

copyFromExpression()

void ls::systems::TransferFunction::copyFromExpression	(	const GiNaC::ex &	tf,
		const GiNaC::ex &	symbol
	)

Copies transfer function coefficients from the given symbolic expression.

Parameters

tf	Transfer function expression.
symbol	Symbol used for the independent variable.

getDen()

Eigen::MatrixXd ls::systems::TransferFunction::getDen

(

)

const

Gets denominator coefficients.

Returns

Denominator coefficients.

getDenDegree()

long ls::systems::TransferFunction::getDenDegree

(

)

const

Returns polynomial degree of the denominator.

Returns

denominator degree.

getDenExpression()

GiNaC::ex ls::systems::TransferFunction::getDenExpression

(

const GiNaC::ex &

symbol

)

const

Generates a symbolic expression of the denominator polynomial.

Parameters

symbol

Symbol to use for the independent variable.

Returns

GiNaC expression of the denominator polynomial.

getExpression()

GiNaC::ex ls::systems::TransferFunction::getExpression

(

const GiNaC::ex &

symbol

)

const

Generates a symbolic expression of the transfer function.

Parameters

symbol

Symbol to use for the independent variable.

Returns

GiNaC expression of the transfer function.

getNum()

Eigen::MatrixXd ls::systems::TransferFunction::getNum

(

)

const

Gets numerator coefficients.

Returns

Numerator coefficients.

getNumDegree()

long ls::systems::TransferFunction::getNumDegree

(

)

const

Returns polynomial degree of the numerator.

Returns

Numerator degree.

getNumExpression()

GiNaC::ex ls::systems::TransferFunction::getNumExpression

(

const GiNaC::ex &

symbol

)

const

Generates a symbolic expression of the numerator polynomial.

Parameters

symbol

Symbol to use for the independent variable.

Returns

GiNaC expression of the numerator polynomial.

normalized()

ls::systems::TransferFunction ls::systems::TransferFunction::normalized

(

)

const

Creates normalized transfer function.

Returns

Normalized transfer function.

setDen()

void ls::systems::TransferFunction::setDen

(

const Eigen::MatrixXd &

den

)

Set denominator coefficients.

Parameters

den	Denominator coefficients.

setNum()

void ls::systems::TransferFunction::setNum

(

const Eigen::MatrixXd &

num

)

Sets numerator coefficients.

Parameters

num	Numerator coefficients.

toDiscreteStateSpace() [1/2]

ls::systems::StateSpace ls::systems::TransferFunction::toDiscreteStateSpace

(

double

dt

)

const

Converts transfer function to discrete-time state space object.

Note

This method uses the backward difference method by default.

See also

ls::analysis::BilinearTransformation::c2dBwdDiff

Parameters

dt	Sampling period.

Returns

Discrete-time state space system.

toDiscreteStateSpace() [2/2]

ls::systems::StateSpace ls::systems::TransferFunction::toDiscreteStateSpace	(	double	dt,
		double	alpha
	)		const

Convert transfer function to discrete-time state space object.

This method adds the option to set alpha in the generalized bilinear transform.

Parameters

dt	Sampling period.
alpha	Generalized bilinear transform parameter.

Returns

Discrete-time state space system.

toStateSpace()

ls::systems::StateSpace ls::systems::TransferFunction::toStateSpace

(

)

const

Converts transfer function to state space object.

Returns

TState space object.

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

• Lodestar/systems/TransferFunction.hpp
• Lodestar/systems/TransferFunction.cpp