Two-dimensional test function based on the formula $$f(\mathbf{x}) = 0.25 x_1^4 - 0.5 x_1^2 + 0.1 x_1 + 0.5 x_2^2$$ with \(\mathbf{x}_1, \mathbf{x}_2 \in [-10, 10]\).
makeAluffiPentiniFunction()[smoof_single_objective_function]
This functions is also know as the Zirilli function.