Hi @jhannyj, welcome to the forum ![]()
MOA is for solving multi-objective (vector-valued) optimization problems, not for finding multiple solutions to a scalar-valued optimization problem.
HiGHS does not support finding multiple solutions.
You could do something like this, where you solve once, add a constraint on optimal objective value, and then try to find a diversity of solutions:
using JuMP, HiGHS
import MultiObjectiveAlgorithms as MOA
model = Model(HiGHS.Optimizer)
@variable(model, x[1:n] >= 0)
@constraint(model, A' * x .>= f)
@objective(model, Min, b' * x)
optimize!(model)
@constraint(model, b' * x == objective_value(model))
@objective(model, Min, x) # objective is now a vector
set_optimizer(model, () -> MOA.Optimizer(HiGHS.Optimizer))
optimize!(model)
[value(x; result = i) for i in 1:result_count(model)]