Description

Two-dimensional test function based on the formula

f(\mathbf{x}) = (x_1^4 + x_2^4 + 2 x_1^2 x_2^2 - 4 x_1 + 3

with \mathbf{x}_1, \mathbf{x}_2 \in [-2000, 2000].

Usage

Value

[smoof_single_objective_function]

References

See http://al-roomi.org/benchmarks/unconstrained/2-dimensions/116-engvall-s-function.