roboptim::ConstantFunction Class Reference
[Mathematical functions]

Constant function. More...

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

Inheritance diagram for roboptim::ConstantFunction:
roboptim::LinearFunction roboptim::QuadraticFunction roboptim::TwiceDerivableFunction roboptim::DerivableFunction roboptim::Function

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.

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.

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:
offset constant function offset
roboptim::ConstantFunction::~ConstantFunction (  )  throw ()

Member Function Documentation

void roboptim::ConstantFunction::impl_compute ( result_t result,
const argument_t argument 
) const throw () [protected, virtual]

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:
result result will be stored in this vector
argument point 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 () [protected, virtual]

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:
gradient gradient will be store in this argument
argument point where the gradient will be computed
functionId evaluated function id in the split representation

Implements roboptim::DerivableFunction.

void roboptim::ConstantFunction::impl_jacobian ( jacobian_t jacobian,
const argument_t arg 
) const throw () [protected, virtual]

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:
jacobian jacobian will be store in this argument
arg point 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:
o output stream used for display
Returns:
output stream

Reimplemented from roboptim::LinearFunction.

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