Borg: stop when MaxRestarts is reached

Author: alyst

src/borg_moea.jl

@@ -28,6 +28,7 @@ mutable struct BorgMOEA{FS<:FitnessScheme,V<:Evaluator,P<:Population,M<:GeneticO
     wrecombinate_update_period::Int
     restart_check_period::Int
     max_steps_without_ϵ_progress::Int
+    max_restarts::Union{Int, Nothing} # how many restarts before termination
 
     recombinate::Vector{CrossoverOperator} # recombination operators
 
@@ -53,7 +54,7 @@ mutable struct BorgMOEA{FS<:FitnessScheme,V<:Evaluator,P<:Population,M<:GeneticO
                 params[:τ], params[:γ], params[:γ_δ], params[:PopulationSize],
                 Categorical(ones(length(recombinate))/length(recombinate)),
                 params[:θ], params[:ζ], params[:OperatorsUpdatePeriod], params[:RestartCheckPeriod],
-                params[:MaxStepsWithoutEpsProgress],
+                params[:MaxStepsWithoutEpsProgress], params[:MaxRestarts],
                 recombinate,
                 TournamentSelector(fit_scheme, ceil(Int, params[:τ]*popsize(pop))), modify, embed)
     end
@@ -68,7 +69,8 @@ const BorgMOEA_DefaultParameters = chain(EpsBoxArchive_DefaultParameters, Params
     :ζ => 1.0,        # dampening coefficient for recombination operator weights
     :RestartCheckPeriod => 1000,
     :OperatorsUpdatePeriod => 100,
-    :MaxStepsWithoutEpsProgress => 100
+    :MaxStepsWithoutEpsProgress => 100,
+    :MaxRestarts => nothing,
 ))
 
 function borg_moea(problem::OptimizationProblem, options::Parameters = EMPTY_PARAMS)
@@ -120,6 +122,10 @@ function step!(alg::BorgMOEA)
     return alg
 end
 
+check_stop_condition(alg::BorgMOEA, ctrl) =
+    isnothing(alg.max_restarts) || (alg.n_restarts < alg.max_restarts) ? "" :
+    "Max number of restarts ($(alg.max_restarts)) reached"
+
 # "kernel function" of step() that would specialize to given xover operator type
 function recombinate!(alg::BorgMOEA, recomb_op_ix::Int, recomb_op::CrossoverOperator)
     # select parents for recombination

test/test_borg_moea.jl

@@ -14,4 +14,11 @@
         @test BlackBoxOptim.IGD(BlackBoxOptim.CEC09_Unconstrained_Set[8].opt_value, pareto_frontier(res),
                                 fitness_scheme(res), Val{length(best_candidate(res))}) < 0.13
     end
+    @testset "MaxRestarts option" begin
+        res = bboptimize(BlackBoxOptim.Schaffer1Family; Method=:borg_moea,
+                         FitnessScheme=ParetoFitnessScheme{2}(is_minimizing=true),
+                         SearchRange=(-10.0, 10.0), NumDimensions=2, ϵ=0.01,
+                         MaxRestarts=3, MaxSteps=100000, TraceMode=:silent)
+        @test BlackBoxOptim.general_stop_reason(res) == "Max number of restarts (3) reached"
+    end
 end