Domain Reduction

Duality-Based Bound Tightening

Variable bound tightening based on the duality multipliers are supported.

EAGO.variable_dbbt!Function
variable_dbbt!(n::NodeBB, mult_lo::Vector{Float64}, mult_hi::Vector{Float64}, LBD::Float64, UBD::Float64, nx::Int64)

Tighten the bounds of the _current_node using the current global upper bound and the duality information obtained from the relaxation.

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Special Forms

Bound tightening for linear forms, univariate quadratic forms, and bivariate quadratic forms are also supported.

EAGO.fbbt!Function
fbbt!(m::GlobalOptimizer, f::T)

Performs feasibility-based bound tightening on a back-end constraint and returns true if it is feasible or false if it is infeasible.

Options for T (all are subtypes of AbstractEAGOConstraint):

  • AffineFunctionIneq
  • AffineFunctionEq
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Constraint Propagation

EAGO contains a constraint propagation architecture that supported forward and reverse evaluation of set-valued functions on the directed acyclic graph (DAG). The interval contractor and reverse McCormick relaxation-based contractors are currently available.

Optimization-Based Bound Tightening

EAGO makes use of an optimization-based bound tightening scheme using filtering and greedy ordering as detailed in: Gleixner, A.M., Berthold, T., Müller, B. et al. J Glob Optim (2017) 67: 731. https://doi.org/10.1007/s10898-016-0450-4.

EAGO.obbt!Function

Performs OBBT with filtering and greedy ordering as detailed in: Gleixner, A.M., Berthold, T., Müller, B. et al. J Glob Optim (2017) 67: 731. https://doi.org/10.1007/s10898-016-0450-4

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EAGO.trivial_filtering!Method
trivial_filtering!(m::GlobalOptimizer{R, S, Q<:ExtensionType}, n::NodeBB)

Excludes OBBT on variable indices that are tight for the solution of the relaxation.

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EAGO.bool_indx_diff!Method
bool_indx_diff!(z::Vector{Bool}, x::Vector{Bool}, y::Vector{Bool}) -> Vector{Bool}

Utility function used to set vector of booleans z to x & ~y. Avoids the generation of conversion of the BitArray created by broadcasting logical operators.

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