CostModelSumTpl< _Scalar > Class Template Reference

Summation of individual cost models. More...

#include <crocoddyl/core/costs/cost-sum.hpp>

Public Types
typedef CostDataAbstractTpl< Scalar >	CostDataAbstract
typedef std::map< std::string, boost::shared_ptr< CostDataAbstract > >	CostDataContainer
typedef CostDataSumTpl< Scalar >	CostDataSum
typedef CostItemTpl< Scalar >	CostItem
typedef CostModelAbstractTpl< Scalar >	CostModelAbstract
typedef std::map< std::string, boost::shared_ptr< CostItem > >	CostModelContainer
typedef DataCollectorAbstractTpl< Scalar >	DataCollectorAbstract
typedef MathBaseTpl< Scalar >	MathBase
typedef MathBase::MatrixXs	MatrixXs
typedef StateAbstractTpl< Scalar >	StateAbstract
typedef MathBase::VectorXs	VectorXs

Public Member Functions
	CostModelSumTpl (boost::shared_ptr< StateAbstract > state)
	Initialize the cost-sum model. More...
	CostModelSumTpl (boost::shared_ptr< StateAbstract > state, const std::size_t nu)
	Initialize the cost-sum model. More...
void	addCost (const std::string &name, boost::shared_ptr< CostModelAbstract > cost, const Scalar weight, const bool active=true)
	Add a cost item. More...
void	calc (const boost::shared_ptr< CostDataSum > &data, const Eigen::Ref< const VectorXs > &x)
	Compute the total cost value for nodes that depends only on the state. More...
void	calc (const boost::shared_ptr< CostDataSum > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u)
	Compute the total cost value. More...
void	calcDiff (const boost::shared_ptr< CostDataSum > &data, const Eigen::Ref< const VectorXs > &x)
	Compute the Jacobian and Hessian of the total cost for nodes that depends on the state only. More...
void	calcDiff (const boost::shared_ptr< CostDataSum > &data, const Eigen::Ref< const VectorXs > &x, const Eigen::Ref< const VectorXs > &u)
	Compute the Jacobian and Hessian of the total cost. More...
void	changeCostStatus (const std::string &name, const bool active)
	Change the cost status. More...
boost::shared_ptr< CostDataSum >	createData (DataCollectorAbstract *const data)
	Create the cost data. More...
const std::vector< std::string > &	get_active () const
	Return the names of the active costs.
const CostModelContainer &	get_costs () const
	Return the stack of cost models.
const std::vector< std::string > &	get_inactive () const
	Return the names of the inactive costs.
std::size_t	get_nr () const
	Return the dimension of the active residual vector.
std::size_t	get_nr_total () const
	Return the dimension of the total residual vector.
std::size_t	get_nu () const
	Return the dimension of the control input.
const boost::shared_ptr< StateAbstract > &	get_state () const
	Return the state.
bool	getCostStatus (const std::string &name) const
	Return the status of a given cost name. More...
void	removeCost (const std::string &name)
	Remove a cost item. More...

Public Attributes
EIGEN_MAKE_ALIGNED_OPERATOR_NEW typedef _Scalar	Scalar

Friends
template<class Scalar >
std::ostream &	operator<< (std::ostream &os, const CostModelSumTpl< Scalar > &model)
	Print information on the stack of costs.

Detailed Description

template<typename _Scalar>
class crocoddyl::CostModelSumTpl< _Scalar >

Summation of individual cost models.

This class serves to manage a set of added cost models. The cost functions might active or inactive, with this approach we avoid dynamic allocation of memory. Each cost model is added through addCost, where the weight and its status can be defined.

The main computations are carring out in calc() and calcDiff() routines. calc() computes the costs (and its residuals) and calcDiff() computes the derivatives of the cost functions (and its residuals). Concretely speaking, calcDiff() builds a linear-quadratic approximation of the total cost function with the form: \(\mathbf{\ell_x}\in\mathbb{R}^{ndx}\), \(\mathbf{\ell_u}\in\mathbb{R}^{nu}\), \(\mathbf{\ell_{xx}}\in\mathbb{R}^{ndx\times ndx}\), \(\mathbf{\ell_{xu}}\in\mathbb{R}^{ndx\times nu}\), \(\mathbf{\ell_{uu}}\in\mathbb{R}^{nu\times nu}\) are the Jacobians and Hessians, respectively.

See also

CostModelAbstractTpl, calc(), calcDiff(), createData()

Definition at line 65 of file cost-sum.hpp.

Constructor & Destructor Documentation

CostModelSumTpl() [1/2]

CostModelSumTpl	(	boost::shared_ptr< StateAbstract >	state,
		const std::size_t	nu
	)

Initialize the cost-sum model.

Parameters

[in]	state	State description
[in]	nu	Dimension of control vector

CostModelSumTpl() [2/2]

CostModelSumTpl ( boost::shared_ptr< StateAbstract >  state )

explicit

Initialize the cost-sum model.

The default nu value is obtained from StateAbstractTpl::get_nv().

Parameters

[in]

state

State description

Member Function Documentation

addCost()

void addCost	(	const std::string &	name,
		boost::shared_ptr< CostModelAbstract >	cost,
		const Scalar	weight,
		const bool	active = true
	)

Add a cost item.

Parameters

[in]	name	Cost name
[in]	cost	Cost model
[in]	weight	Cost weight
[in]	active	True if the cost is activated (default true)

removeCost()

void removeCost

(

const std::string &

name

)

Remove a cost item.

Parameters

[in]

name

Cost name

changeCostStatus()

void changeCostStatus	(	const std::string &	name,
		const bool	active
	)

Change the cost status.

Parameters

[in]	name	Cost name
[in]	active	Cost status (true for active and false for inactive)

calc() [1/2]

void calc	(	const boost::shared_ptr< CostDataSum > &	data,
		const Eigen::Ref< const VectorXs > &	x,
		const Eigen::Ref< const VectorXs > &	u
	)

Compute the total cost value.

Parameters

[in]	data	Cost data
[in]	x	State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)
[in]	u	Control input \(\mathbf{u}\in\mathbb{R}^{nu}\)

calc() [2/2]

void calc	(	const boost::shared_ptr< CostDataSum > &	data,
		const Eigen::Ref< const VectorXs > &	x
	)

Compute the total cost value for nodes that depends only on the state.

It updates the total cost based on the state only. This function is used in the terminal nodes of an optimal control problem.

Parameters

[in]	data	Cost data
[in]	x	State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)

calcDiff() [1/2]

void calcDiff	(	const boost::shared_ptr< CostDataSum > &	data,
		const Eigen::Ref< const VectorXs > &	x,
		const Eigen::Ref< const VectorXs > &	u
	)

Compute the Jacobian and Hessian of the total cost.

Parameters

[in]	data	Cost data
[in]	x	State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)
[in]	u	Control input \(\mathbf{u}\in\mathbb{R}^{nu}\)

calcDiff() [2/2]

void calcDiff	(	const boost::shared_ptr< CostDataSum > &	data,
		const Eigen::Ref< const VectorXs > &	x
	)

Compute the Jacobian and Hessian of the total cost for nodes that depends on the state only.

It updates the Jacobian and Hessian of the total cost based on the state only. This function is used in the terminal nodes of an optimal control problem.

Parameters

[in]	data	Cost data
[in]	x	State point \(\mathbf{x}\in\mathbb{R}^{ndx}\)
[in]	u	Control input \(\mathbf{u}\in\mathbb{R}^{nu}\)

createData()

boost::shared_ptr<CostDataSum> createData

(

DataCollectorAbstract *const

data

)

Create the cost data.

The default data contains objects to store the values of the cost, residual vector and their derivatives (first and second order derivatives). However, it is possible to specialized this function is we need to create additional data, for instance, to avoid dynamic memory allocation.

Parameters

data	Data collector

Returns

the cost data

getCostStatus()

bool getCostStatus

(

const std::string &

name

)

const

Return the status of a given cost name.

Parameters

[in]

name

Cost name

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

• include/crocoddyl/core/costs/cost-sum.hpp