MiesOperator: Operator Base Class

MiesOperatorR Documentation

Operator Base Class

Description

Base class representing MIES-operators: Recombinator, Mutator, and Selector.

Operators perform a specific function within ES algorithms, and by exchanging them, the character of ES algorithms can be modified. Operators operate on collections of individuals and return modified individuals (mutated or recombined) or indices of selected individuals. Operators can be combined using MutatorCombination / RecombinatorCombination and other operators wrappers.

Before applying operators, they have to be primed for the domain of the individuals which they are operating on; this is done using the ⁠$prime()⁠ function. Afterwards, the ⁠$operate()⁠ function may be called with a data.frame of individuals that fall into this domain. ⁠$operate()⁠ may be called multiple times after priming, and a once primed operator can be primed again for a different domain by calling ⁠$prime()⁠ agian (which forgets the old priming).

Inheriting

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

In most cases, the MiesOperator class should not be inherited from, directly; instead, the operator classes (Recombinator, Mutator, Selector) or their subclasses should be inherited.

Active bindings

param_set

(ParamSet)
Configuration parameters of the MiesOperator object. Read-only.

param_classes

(character)
Classes of parameters that the operator can handle, contains any of "ParamLgl", "ParamInt", "ParamDbl", "ParamFct". Read-only.

packages

(character)
Packages needed for the operator. Read-only.

dict_entry

(character(1) | NULL)
Key of this class in its respective Dictionary. Is NULL if this class it not (known to be) in a Dictionary. Read-only.

dict_shortaccess

(character(1) | NULL)
Name of Dictionary short-access function where an object of this class can be retrieved. Is NULL if this class is not (known to be) in a Dictionary with a short-access function. Read-only.

endomorphism

(logical(1))
Whether the output of ⁠$operate()⁠ is a data.frame / data.table in the same domain as its input. Read-only.

primed_ps

(ParamSet | NULL)
ParamSet on which the MiesOperator is primed. Is NULL if it has not been primed. Writing to this acrive binding calls ⁠$prime()⁠.

is_primed

(logical(1))
Whether the MiesOperator was primed before. Is FALSE exactly when ⁠$primed_ps⁠ is NULL. Read-only.

man

(character(1))
Name of this class, in the form ⁠<package>::<classname>⁠. Used by the ⁠$help()⁠ method.

Methods

Public methods


Method new()

Initialize base class components of the MiesOperator.

Usage
MiesOperator$new(
  param_classes = c("ParamLgl", "ParamInt", "ParamDbl", "ParamFct"),
  param_set = ps(),
  packages = character(0),
  dict_entry = NULL,
  dict_shortaccess = NULL,
  own_param_set = quote(self$param_set),
  endomorphism = TRUE
)
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.

dict_shortaccess

(character(1) | NULL)
Name of the Dictionary short access function in which the operator is registered. This is used to inform the user about how to construct a given object. Should ordinarily be one of "mut", "rec", "sel".
The ⁠$dict_shortaccess⁠ 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.

endomorphism

(logical(1))
Whether the private ⁠$.operate()⁠ operation creates a data.table with the same columns as the input (i.e. conforming to the primed ParamSet). If this is TRUE (default), then the return value of ⁠$.operate()⁠ is checked for this and columns are put in the correct order.
The ⁠$endomorphsim⁠ field will reflect this value.


Method repr()

Create a call object representing this operator.

Usage
MiesOperator$repr(
  skip_defaults = TRUE,
  show_params = TRUE,
  show_constructor_args = TRUE,
  ...
)
Arguments
skip_defaults

(logical(1))
Whether to skip construction arguments that have their default value. Default TRUE.

show_params

(logical(1))
Whether to show ParamSet values. Default TRUE.

show_constructor_args

(logical(1))
Whether to show construction args that are not ParamSet values. Default TRUE.

...

(any)
Ignored.


Method print()

Print this operator.

Usage
MiesOperator$print(verbose = FALSE, ...)
Arguments
verbose

(logical(1))
Whether to show all construction arguments, even the ones at default values. Default FALSE.

...

(any)
Ignored.


Method prime()

Prepare the MiesOperator to function on the given ParamSet. This must be called before ⁠$operate()⁠. It may be called multiple times in the lifecycle of the MiesOperator object, and prior primings are forgotten when priming on a new ParamSet. The ParamSet on which the MiesOperator was last primed can be read from ⁠$primed_ps⁠.

Usage
MiesOperator$prime(param_set)
Arguments
param_set

(ParamSet)
The ParamSet to which all values tables passed to ⁠$operate()⁠ will need to conform to. May only contiain Domain objects that conform to the classes listed in ⁠$param_classes⁠.

Returns

invisible self.


Method operate()

Operate on the given individuals. This calls private ⁠$.operate()⁠, which must be overloaded by an inheriting class, passing through all function arguments after performing some checks.

Usage
MiesOperator$operate(values, ...)
Arguments
values

(data.frame)
Individuals to operate on. Must pass the check of the ParamSet given in the last ⁠$prime()⁠ call and may not have any missing components.

...

(any)
Depending on the concrete class, passed on to ⁠$.operate()⁠.

Returns

data.frame: the result of the operation. If the input was a data.table instead of a data.frame, the output is also data.table.


Method help()

Run utils::help() for this object.

Usage
MiesOperator$help(help_type = getOption("help_type"))
Arguments
help_type

(character(1))
One of "text", "html", or "pdf": The type of help page to open. Defaults to the "help_type" option.

Returns

help_files_with_dopic object, which opens the help page.


Method clone()

The objects of this class are cloneable with this method.

Usage
MiesOperator$clone(deep = FALSE)
Arguments
deep

Whether to make a deep clone.

See Also

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


miesmuschel documentation built on Sept. 11, 2024, 8:23 p.m.