shark::ConstrainedSphere Struct Reference

Constrained Sphere function. More...

#include <shark/ObjectiveFunctions/Benchmarks/ConstrainedSphere.h>

+ Inheritance diagram for shark::ConstrainedSphere:

Public Member Functions

 ConstrainedSphere (std::size_t numberOfVariables=5, std::size_t m=1)
 
std::string name () const
 From INameable: return the class name. More...
 
std::size_t numberOfVariables () const
 Accesses the number of variables. More...
 
bool hasScalableDimensionality () const
 
void setNumberOfVariables (std::size_t numberOfVariables)
 Adjusts the number of variables if the function is scalable. More...
 
SearchPointType proposeStartingPoint () const
 Proposes a starting point in the feasible search space of the function. More...
 
bool isFeasible (SearchPointType const &input) const
 Tests whether a point in SearchSpace is feasible, e.g., whether the constraints are fulfilled. More...
 
double eval (const SearchPointType &p) const
 Evaluates the objective function for the supplied argument. More...
 
- Public Member Functions inherited from shark::AbstractObjectiveFunction< PointType, ResultT >
const Featuresfeatures () const
 
virtual void updateFeatures ()
 
bool hasValue () const
 returns whether this function can calculate it's function value More...
 
bool hasFirstDerivative () const
 returns whether this function can calculate the first derivative More...
 
bool hasSecondDerivative () const
 returns whether this function can calculate the second derivative More...
 
bool canProposeStartingPoint () const
 returns whether this function can propose a starting point. More...
 
bool isConstrained () const
 returns whether this function can return More...
 
bool hasConstraintHandler () const
 returns whether this function can return More...
 
bool canProvideClosestFeasible () const
 Returns whether this function can calculate thee closest feasible to an infeasible point. More...
 
bool isThreadSafe () const
 Returns true, when the function can be usd in parallel threads. More...
 
bool isNoisy () const
 Returns true, when the function can be usd in parallel threads. More...
 
 AbstractObjectiveFunction ()
 Default ctor. More...
 
virtual ~AbstractObjectiveFunction ()
 Virtual destructor. More...
 
virtual void init ()
 
void setRng (random::rng_type *rng)
 Sets the Rng used by the objective function. More...
 
virtual std::size_t numberOfObjectives () const
 
virtual bool hasScalableObjectives () const
 
virtual void setNumberOfObjectives (std::size_t numberOfObjectives)
 Adjusts the number of objectives if the function is scalable. More...
 
std::size_t evaluationCounter () const
 Accesses the evaluation counter of the function. More...
 
AbstractConstraintHandler< SearchPointType > const & getConstraintHandler () const
 Returns the constraint handler of the function if it has one. More...
 
virtual void closestFeasible (SearchPointType &input) const
 If supported, the supplied point is repaired such that it satisfies all of the function's constraints. More...
 
ResultType operator() (SearchPointType const &input) const
 Evaluates the function. Useful together with STL-Algorithms like std::transform. More...
 
virtual ResultType evalDerivative (SearchPointType const &input, FirstOrderDerivative &derivative) const
 Evaluates the objective function and calculates its gradient. More...
 
virtual ResultType evalDerivative (SearchPointType const &input, SecondOrderDerivative &derivative) const
 Evaluates the objective function and calculates its gradient. More...
 
- Public Member Functions inherited from shark::INameable
virtual ~INameable ()
 

Additional Inherited Members

- Public Types inherited from shark::AbstractObjectiveFunction< PointType, ResultT >
enum  Feature {
  HAS_VALUE = 1, HAS_FIRST_DERIVATIVE = 2, HAS_SECOND_DERIVATIVE = 4, CAN_PROPOSE_STARTING_POINT = 8,
  IS_CONSTRAINED_FEATURE = 16, HAS_CONSTRAINT_HANDLER = 32, CAN_PROVIDE_CLOSEST_FEASIBLE = 64, IS_THREAD_SAFE = 128,
  IS_NOISY = 256
}
 List of features that are supported by an implementation. More...
 
typedef PointType SearchPointType
 
typedef ResultT ResultType
 
typedef boost::mpl::if_< std::is_arithmetic< ResultT >, SearchPointType, RealMatrix >::type FirstOrderDerivative
 
typedef TypedFlags< FeatureFeatures
 This statement declares the member m_features. See Core/Flags.h for details. More...
 
typedef TypedFeatureNotAvailableException< FeatureFeatureNotAvailableException
 
- Protected Member Functions inherited from shark::AbstractObjectiveFunction< PointType, ResultT >
void announceConstraintHandler (AbstractConstraintHandler< SearchPointType > const *handler)
 helper function which is called to announce the presence of an constraint handler. More...
 
- Protected Attributes inherited from shark::AbstractObjectiveFunction< PointType, ResultT >
Features m_features
 
std::size_t m_evaluationCounter
 Evaluation counter, default value: 0. More...
 
AbstractConstraintHandler< SearchPointType > const * m_constraintHandler
 
random::rng_type * mep_rng
 

Detailed Description

Constrained Sphere function.

This is a simple sphere function minimizing \( f(x) = \sum_i^N x_i^2-m \) under the constraints that \( x_i \geq 1\) for \( i = 1,\dots,m \). The minimum is at \( x_1=\dots = x_m = 1\) and \( x_{m+1}=\dots = x_N = 0 \) with function value 0.

This is a simple benchmark for evolutionary algorithms as, the closer the algorithm is to the optimu

Definition at line 47 of file ConstrainedSphere.h.

Constructor & Destructor Documentation

◆ ConstrainedSphere()

Member Function Documentation

◆ eval()

double shark::ConstrainedSphere::eval ( const SearchPointType input) const
inlinevirtual

Evaluates the objective function for the supplied argument.

Parameters
[in]inputThe argument for which the function shall be evaluated.
Returns
The result of evaluating the function for the supplied argument.
Exceptions
FeatureNotAvailableExceptionin the default implementation and if a function does not support this feature.

Reimplemented from shark::AbstractObjectiveFunction< PointType, ResultT >.

Definition at line 91 of file ConstrainedSphere.h.

References shark::AbstractObjectiveFunction< PointType, ResultT >::m_evaluationCounter.

◆ hasScalableDimensionality()

bool shark::ConstrainedSphere::hasScalableDimensionality ( ) const
inlinevirtual

Reimplemented from shark::AbstractObjectiveFunction< PointType, ResultT >.

Definition at line 64 of file ConstrainedSphere.h.

◆ isFeasible()

bool shark::ConstrainedSphere::isFeasible ( SearchPointType const &  input) const
inlinevirtual

Tests whether a point in SearchSpace is feasible, e.g., whether the constraints are fulfilled.

Parameters
[in]inputThe point to be tested for feasibility.
Returns
true if the point is feasible, false otherwise.

Reimplemented from shark::AbstractObjectiveFunction< PointType, ResultT >.

Definition at line 84 of file ConstrainedSphere.h.

◆ name()

std::string shark::ConstrainedSphere::name ( ) const
inlinevirtual

From INameable: return the class name.

Reimplemented from shark::INameable.

Definition at line 57 of file ConstrainedSphere.h.

◆ numberOfVariables()

std::size_t shark::ConstrainedSphere::numberOfVariables ( ) const
inlinevirtual

Accesses the number of variables.

Implements shark::AbstractObjectiveFunction< PointType, ResultT >.

Definition at line 60 of file ConstrainedSphere.h.

Referenced by proposeStartingPoint(), and setNumberOfVariables().

◆ proposeStartingPoint()

SearchPointType shark::ConstrainedSphere::proposeStartingPoint ( ) const
inlinevirtual

Proposes a starting point in the feasible search space of the function.

Returns
The generated starting point.
Exceptions
FeatureNotAvailableExceptionin the default implementation and if a function does not support this feature.

Reimplemented from shark::AbstractObjectiveFunction< PointType, ResultT >.

Definition at line 72 of file ConstrainedSphere.h.

References shark::random::gauss(), shark::AbstractObjectiveFunction< PointType, ResultT >::mep_rng, and numberOfVariables().

◆ setNumberOfVariables()

void shark::ConstrainedSphere::setNumberOfVariables ( std::size_t  numberOfVariables)
inlinevirtual

Adjusts the number of variables if the function is scalable.

Parameters
[in]numberOfVariablesThe new dimension.

Reimplemented from shark::AbstractObjectiveFunction< PointType, ResultT >.

Definition at line 68 of file ConstrainedSphere.h.

References numberOfVariables().


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