Ikeda–Kita–Kobayashi (IKK)
This family is represented by the IKK1 constructor. The problem is drawn from “Failure of Pareto-based MOEAs: does non-dominated really mean near to optimal?” [13].
Overview
IKK1 has nvar = 2 and nobj = 3. Its componentwise bounds are shown below.
| Problem | nvar | nobj | Lower bound | Upper bound |
|---|---|---|---|---|
IKK1 | 2 | 3 | -50.0 | 50.0 |
An analytical Jacobian is registered. Hessians are not registered. The catalog metadata classifies all three objectives as not strictly convex (:not_strictly_convex).
Mathematical formulation
Let $F:\mathbb{R}^2 \to \mathbb{R}^3$ be defined by $F(x)=(f_1(x),f_2(x),f_3(x))$, where $x=(x_1,x_2) \in \mathbb{R}^2$. The objectives are
\[\begin{aligned} f_1(x) &= x_1^2,\\ f_2(x) &= (x_1-20)^2,\\ f_3(x) &= x_2^2. \end{aligned}\]
Usage
julia> using MOProblems
julia> using Random
julia> prob = IKK1();
julia> lower, upper = recommended_bounds(prob);
julia> rng = MersenneTwister(1234);
julia> α = rand(rng, prob.nvar);
julia> x = lower .+ α .* (upper .- lower);
julia> values = eval_f(prob, x);
julia> J = eval_jacobian(prob, x);
julia> (length(values), size(J))
(3, (3, 2))Constructor reference
MOProblems.IKK1 — Function
IKK1()Construct the fixed two-variable, three-objective IKK1 problem.
The variables are bounded in [-50, 50]^2. An analytical Jacobian is registered; objective Hessians are not registered.