Mutator {miesmuschel}

Mutator Base Class

Description

Base class representing mutation operations, inheriting from MiesOperator.

Mutations get a table of individuals as input and return a table of modified individuals as output. Individuals are acted on as individuals: every line of output corresponds to the same line of input, and presence or absence of other input lines does not affect the result.

Mutation operations are performed in ES algorithms to facilitate exploration of the search space around individuals.

Inheriting

Mutator is an abstract base class and should be inherited from. Inheriting classes should implement the private ⁠$.mutate()⁠ function. The user of the object calls ⁠$operate()⁠, and the arguments are passed on to private ⁠$.mutate()⁠ after checking that the operator is primed, and that the values argument conforms to the primed domain. Typically, the ⁠$initialize()⁠ function should also be overloaded, and optionally the ⁠$prime()⁠ function; they should call their super equivalents.

In many cases, it is advisable to inherit from one of the abstract subclasses, such as MutatorNumeric, or MutatorDiscrete.

Super class

miesmuschel::MiesOperator -> Mutator

Methods

Public methods

• Mutator$new()

• Mutator$clone()

Inherited methods

• miesmuschel::MiesOperator$help()
• miesmuschel::MiesOperator$operate()
• miesmuschel::MiesOperator$prime()
• miesmuschel::MiesOperator$print()
• miesmuschel::MiesOperator$repr()

Method new()

Initialize base class components of the Mutator.

Usage

Mutator$new(
  param_classes = c("ParamLgl", "ParamInt", "ParamDbl", "ParamFct"),
  param_set = ps(),
  packages = character(0),
  dict_entry = NULL,
  own_param_set = quote(self$param_set)
)

Arguments

param_classes

(character)
Classes of parameters that the operator can handle. May contain any of "ParamLgl", "ParamInt", "ParamDbl", "ParamFct". Default is all of them.
The ⁠$param_classes⁠ field will reflect this value.

param_set

(ParamSet | list of expression)
Strategy parameters of the operator. This should be created by the subclass and given to super$initialize(). If this is a ParamSet, it is used as the MiesOperator's ParamSet directly. Otherwise it must be a list of expressions e.g. created by alist() that evaluate to ParamSets, possibly referencing self and private. These ParamSet are then combined using a ParamSetCollection. Default is the empty ParamSet.
The ⁠$param_set⁠ field will reflect this value.

packages

(character) Packages that need to be loaded for the operator to function. This should be declared so these packages can be loaded when operators run on parallel instances. Default is character(0).
The ⁠$packages⁠ field will reflect this values.

dict_entry

(character(1) | NULL)
Key of the class inside the Dictionary (usually one of dict_mutators, dict_recombinators, dict_selectors), where it can be retrieved using a short access function. May be NULL if the operator is not entered in a dictionary.
The ⁠$dict_entry⁠ field will reflect this value.

own_param_set

(language)
An expression that evaluates to a ParamSet indicating the configuration parameters that are entirely owned by this operator class (and not proxied from a construction argument object). This should be quote(self$param_set) (the default) when the param_set argument is not a list of expressions.

Method clone()

The objects of this class are cloneable with this method.

Usage

Mutator$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

See Also

Other base classes: Filtor, FiltorSurrogate, MiesOperator, MutatorDiscrete, MutatorNumeric, OperatorCombination, Recombinator, RecombinatorPair, Scalor, Selector, SelectorScalar

Other mutators: MutatorDiscrete, MutatorNumeric, OperatorCombination, dict_mutators_cmpmaybe, dict_mutators_erase, dict_mutators_gauss, dict_mutators_maybe, dict_mutators_null, dict_mutators_proxy, dict_mutators_sequential, dict_mutators_unif