cma.sigma_adaptation.CMAAdaptSigmaMedianImprovement

class documentation

class CMAAdaptSigmaMedianImprovement(CMAAdaptSigmaBase):

Compares median fitness to the 27%tile fitness of the previous iteration, see Ait ElHara et al, GECCO 2013.

>>> import cma
>>> es = cma.CMAEvolutionStrategy(3 * [1], 1,
... {'AdaptSigma':cma.sigma_adaptation.CMAAdaptSigmaMedianImprovement,
...  'verbose': -9})
>>> assert es.optimize(cma.ff.elli).result[1] < 1e-9
>>> assert es.result[2] < 2000

Method	`__init__`	Undocumented
Method	`initialize`	late initialization using attributes `N` and `popsize`
Method	`update`	update `es.sigma`
Instance Variable	`c`	Undocumented
Instance Variable	`damp`	Undocumented
Instance Variable	`fit`	Undocumented
Instance Variable	`index_to_compare`	Undocumented
Instance Variable	`s`	Undocumented

Inherited from CMAAdaptSigmaBase:

Method	`check_consistency`	make consistency checks with a `CMAEvolutionStrategy` instance as input
Method	`hsig`	return "OK-signal" for rank-one update, `True` (OK) or `False` (stall rank-one update), based on the length of an evolution path
Method	`initialize_base`	set parameters and state variable based on dimension, mueff and possibly further options.
Method	`update2`	return sigma change factor and update self.delta.
Instance Variable	`cs`	Undocumented
Instance Variable	`delta`	cumulated effect of adaptation
Instance Variable	`is_initialized_base`	Undocumented
Instance Variable	`ps`	Undocumented
Method	`_update_ps`	update the isotropic evolution path.
Instance Variable	`_ps_updated_iteration`	Undocumented

def __init__(self, **kwargs): ¶

overrides cma.sigma_adaptation.CMAAdaptSigmaBase.__init__

Undocumented

def initialize(self, es): ¶

late initialization using attributes N and popsize

def update(self, es, **kwargs): ¶

overrides cma.sigma_adaptation.CMAAdaptSigmaBase.update

update es.sigma

Parameters
es	`CMAEvolutionStrategy` class instance
**kwargs	whatever else is needed to update `es.sigma`, which should be none.

c: float = ¶

Undocumented

damp = ¶

Undocumented

fit = ¶

Undocumented

index_to_compare = ¶

Undocumented

s: int = ¶

Undocumented