Merge pull request #272 from scipopt/presolving-attr

presolving attribute

src/MOI_wrapper.jl

@@ -262,6 +262,28 @@ function MOI.set(o::Optimizer, ::MOI.Name, name::String)
  @SCIP_CALL SCIPsetProbName(o, name)
 end
 
+"""
+ Presolving
+
+Attribute for activating presolving in SCIP.
+"""
+struct Presolving <: MOI.AbstractOptimizerAttribute end
+
+MOI.supports(o::Optimizer, ::Presolving) = true
+
+function MOI.get(o::Optimizer, ::Presolving)
+ return MOI.get(o, MOI.RawOptimizerAttribute("presolving/maxrounds")) != 0
+end
+
+function MOI.set(o::Optimizer, ::Presolving, value::Bool)
+ param = MOI.RawOptimizerAttribute("presolving/maxrounds")
+ if value
+ MOI.set(o, param, -1) # max presolving rounds
+ else
+ MOI.set(o, param, 0) # no presolving
+ end
+end
+
 function MOI.get(o::Optimizer, ::MOI.NumberOfConstraints{F,S}) where {F,S}
  return haskey(o.constypes, (F, S)) ? length(o.constypes[F, S]) : 0
 end

test/MOI_additional.jl

@@ -519,3 +519,41 @@ end
  @test ≈(MOI.get(model, MOI.VariablePrimal(), z2), T(1), config)
  end
 end
+
+@testset "Presolving $presolving" for presolving in (true, false)
+ optimizer = SCIP.Optimizer(; display_verblevel=0)
+ atol, rtol = 1e-6, 1e-6
+
+ x, y = MOI.add_variables(optimizer, 2)
+ MOI.add_constraint(optimizer, x, MOI.GreaterThan(0.0))
+ MOI.add_constraint(optimizer, y, MOI.GreaterThan(0.0))
+
+ c = MOI.add_constraint(
+ optimizer,
+ MOI.ScalarAffineFunction(
+ MOI.ScalarAffineTerm.([1.0, 1.0], [x, y]),
+ 0.0,
+ ),
+ MOI.LessThan(1.0),
+ )
+
+ MOI.set(
+ optimizer,
+ MOI.ObjectiveFunction{MOI.ScalarAffineFunction{Float64}}(),
+ MOI.ScalarAffineFunction(
+ MOI.ScalarAffineTerm.([1.0, 2.0], [x, y]),
+ 0.0,
+ ),
+ )
+ MOI.set(optimizer, MOI.ObjectiveSense(), MOI.MAX_SENSE)
+
+ @test MOI.get(optimizer, SCIP.Presolving()) == true
+ MOI.set(optimizer, SCIP.Presolving(), presolving)
+ @test MOI.get(optimizer, SCIP.Presolving()) == presolving
+
+ # after optimize
+ MOI.optimize!(optimizer)
+
+ MOI.set(optimizer, SCIP.Presolving(), presolving)
+ @test MOI.get(optimizer, SCIP.Presolving()) == presolving
+end