saealib.LinearRankSelection#

class saealib.LinearRankSelection[source]#

Bases: ParentSelection

Parent selection using linear rank-based probabilities.

Selection probability is proportional to rank: the best individual has the highest probability and the worst has the lowest. This avoids numerical issues with raw fitness values (negative values, scale sensitivity) while preserving a fitness-proportionate behaviour.

Methods

`__init__`
`contract`	Return the linear-rank-selection contract.
`select`	Execute linear rank selection.

Method Details

LinearRankSelection.__init__()[source]#

LinearRankSelection.contract()[source]#

Return the linear-rank-selection contract.

Return type:: ComponentContract

LinearRankSelection.select(ctx, population, n_pair, n_parents, rng=Generator(PCG64) at 0x7F7917917CA0)[source]#

Execute linear rank selection.

Parameters:

ctx (ExecutionContext) – Optimization context.
population (Population) – Population to select from.
n_pair (int) – Number of pairs to select.
n_parents (int) – Number of parents per pair.
rng (np.random.Generator, optional) – Random number generator, by default np.random.default_rng()

Returns:

Selected parent indices. shape = (n_pair, n_parents)

Return type:

np.ndarray