def branin(x):
    y = ((5.1 / (4. * pi ** 2.)) * x[0] ** 2. + 5. * x[0] / pi - 6. - x[1]) ** 2. + 10. * (1. - 1. / (8. * pi)) * cos(
        x[0]) + 10.
    return y
dataset/ETHPy150Open OpenMDAO/OpenMDAO/openmdao/surrogate_models/test/test_kriging.py/branin/swapped operands of `-`