roboptim::ConstantFunction Class Reference

Constant function. More...

#include <roboptim/core/constant-function.hh>

+ Inheritance diagram for roboptim::ConstantFunction:

List of all members.

Public Member Functions

 ConstantFunction (const vector_t &offset) throw ()
 Build an constant function.
 ~ConstantFunction () throw ()
virtual std::ostream & print (std::ostream &) const throw ()
 Display the function on the specified output stream.
- Public Member Functions inherited from roboptim::LinearFunction
 LinearFunction (size_type inputSize, size_type outputSize=1, std::string name=std::string()) throw ()
 Concrete class constructor should call this constructor.
- Public Member Functions inherited from roboptim::QuadraticFunction
 QuadraticFunction (size_type inputSize, size_type outputSize=1, std::string name=std::string()) throw ()
 Concrete class constructor should call this constructor.
- Public Member Functions inherited from roboptim::TwiceDerivableFunction
hessianSize_t hessianSize () const throw ()
 Return the size of a hessian.
bool isValidHessian (const hessian_t &hessian) const throw ()
 Check if the hessian is valid (check sizes).
hessian_t hessian (const argument_t &argument, size_type functionId=0) const throw ()
 Compute the hessian at a given point.
void hessian (hessian_t &hessian, const argument_t &argument, size_type functionId=0) const throw ()
 Compute the hessian at a given point.
- Public Member Functions inherited from roboptim::DerivableFunction
size_type gradientSize () const throw ()
 Return the gradient size.
jacobianSize_t jacobianSize () const throw ()
 Return the jacobian size as a pair.
bool isValidGradient (const gradient_t &gradient) const throw ()
 Check if the gradient is valid (check size).
bool isValidJacobian (const jacobian_t &jacobian) const throw ()
 Check if the jacobian is valid (check sizes).
jacobian_t jacobian (const argument_t &argument) const throw ()
 Computes the jacobian.
void jacobian (jacobian_t &jacobian, const argument_t &argument) const throw ()
 Computes the jacobian.
gradient_t gradient (const argument_t &argument, size_type functionId=0) const throw ()
 Computes the gradient.
void gradient (gradient_t &gradient, const argument_t &argument, size_type functionId=0) const throw ()
 Computes the gradient.
- Public Member Functions inherited from roboptim::Function
bool isValidResult (const result_t &result) const throw ()
 Check the given result size is valid.
size_type inputSize () const throw ()
 Return the input size (i.e. argument's vector size).
size_type outputSize () const throw ()
 Return the output size (i.e. result's vector size).
virtual ~Function () throw ()
 Trivial destructor.
result_t operator() (const argument_t &argument) const throw ()
 Evaluate the function at a specified point.
void operator() (result_t &result, const argument_t &argument) const throw ()
 Evaluate the function at a specified point.
const std::string & getName () const throw ()
 Get function name.

Protected Member Functions

void impl_compute (result_t &, const argument_t &) const throw ()
 Function evaluation.
void impl_gradient (gradient_t &, const argument_t &, size_type=0) const throw ()
 Gradient evaluation.
void impl_jacobian (jacobian_t &, const argument_t &) const throw ()
 Jacobian evaluation.
- Protected Member Functions inherited from roboptim::LinearFunction
void impl_hessian (hessian_t &hessian, const argument_t &argument, size_type functionId=0) const throw ()
 Hessian evaluation.

Detailed Description

Constant function.

 Implement a constant function using the formula:

\[f(x) = offset\]

where $offset$ is set when the class is instantiated.

Examples:
constant-function.cc, and problem-cc.cc.

Constructor & Destructor Documentation

roboptim::ConstantFunction::ConstantFunction ( const vector_t offset) throw ()

Build an constant function.

Parameters:
offsetconstant function offset
roboptim::ConstantFunction::~ConstantFunction ( ) throw ()

Member Function Documentation

void roboptim::ConstantFunction::impl_compute ( result_t result,
const argument_t argument 
) const throw ()
protectedvirtual

Function evaluation.

Evaluate the function, has to be implemented in concrete classes.

Warning:
Do not call this function directly, call operator()(result_t&, const argument_t&) const throw () instead.
Parameters:
resultresult will be stored in this vector
argumentpoint at which the function will be evaluated

Implements roboptim::Function.

void roboptim::ConstantFunction::impl_gradient ( gradient_t gradient,
const argument_t argument,
size_type  functionId = 0 
) const throw ()
protectedvirtual

Gradient evaluation.

Compute the gradient, has to be implemented in concrete classes. The gradient is computed for a specific sub-function which id is passed through the functionId argument.

Warning:
Do not call this function directly, call gradient instead.
Parameters:
gradientgradient will be store in this argument
argumentpoint where the gradient will be computed
functionIdevaluated function id in the split representation

Implements roboptim::DerivableFunction.

void roboptim::ConstantFunction::impl_jacobian ( jacobian_t jacobian,
const argument_t arg 
) const throw ()
protectedvirtual

Jacobian evaluation.

Computes the jacobian, can be overridden by concrete classes. The default behavior is to compute the jacobian from the gradient.

Warning:
Do not call this function directly, call jacobian instead.
Parameters:
jacobianjacobian will be store in this argument
argpoint where the jacobian will be computed

Reimplemented from roboptim::DerivableFunction.

std::ostream & roboptim::ConstantFunction::print ( std::ostream &  o) const throw ()
virtual

Display the function on the specified output stream.

Parameters:
ooutput stream used for display
Returns:
output stream

Reimplemented from roboptim::LinearFunction.

References roboptim::decindent(), roboptim::iendl(), and roboptim::incindent().