def _select_optimizer_cls()

in nevergrad/optimization/optimizerlib.py [0:0]

• 33 lines of code
• 24 McCabe index (conditional complexity)

    def _select_optimizer_cls(self) -> base.OptCls:
        # pylint: disable=too-many-nested-blocks
        assert self.budget is not None
        if self.has_noise and self.has_discrete_not_softmax:
            # noise and discrete: let us merge evolution and bandits.
            cls: base.OptCls = DoubleFastGADiscreteOnePlusOne if self.dimension < 60 else CMA
        else:
            if self.has_noise and self.fully_continuous:
                # This is the real of population control. FIXME: should we pair with a bandit ?
                cls = TBPSA
            else:
                if (
                    self.has_discrete_not_softmax
                    or not self.parametrization.function.metrizable
                    or not self.fully_continuous
                ):
                    cls = DoubleFastGADiscreteOnePlusOne
                else:
                    if self.num_workers > self.budget / 5:
                        if self.num_workers > self.budget / 2.0 or self.budget < self.dimension:
                            cls = MetaRecentering
                        else:
                            cls = NaiveTBPSA
                    else:
                        # Possibly a good idea to go memetic for large budget, but something goes wrong for the moment.
                        if (
                            self.num_workers == 1 and self.budget > 6000 and self.dimension > 7
                        ):  # Let us go memetic.
                            cls = ChainCMAPowell
                        else:
                            if self.num_workers == 1 and self.budget < self.dimension * 30:
                                # One plus one so good in large ratio "dimension / budget".
                                cls = OnePlusOne if self.dimension > 30 else Cobyla
                            else:
                                # DE is great in such a case (?).
                                cls = (
                                    DE if self.dimension > 2000 else CMA if self.dimension > 1 else OnePlusOne
                                )
        return cls