List of selection policies#
Selection policies exposed from C++#
- class pygmo.select_best(rate=1)#
Select best selection policy.
This user-defined selection policy (UDSP) will select the best individuals from a group.
In this context, best means the following:
in single-objective unconstrained problems, individuals are ranked according to their fitness function,
in single-objective constrained problems, individuals are ranked via
in multi-objective unconstrained problems, individuals are ranked via
Note that this user-defined selection policy currently does not support multi-objective constrained problems.
A select best policy is constructed from a rate argument, which can be either an integral or a floating-point value.
If rate is a floating point value in the \(\left[0,1\right]\) range, then it represents a fractional migration rate. That is, it indicates, the fraction of individuals that will be selected from the input population: a value of 0 means that no individuals will be selected, a value of 1 means that all individuals will be selected.
If rate is an integral value, then it represents an absolute migration rate, that is, the exact number of individuals that will be selected from the input population.
See also the docs of the C++ class