On an 2-dimensional domain it is defined by
f(x) = x_1^2 + 2x_2^2 -0.3(3 x_1)-0.4(4 x_2)+0.7f(x) = x_1^2 + 2x_2^2 -0.3cos(3 x_1)-0.4cos(4 x_2)+0.7
and is usually evaluated on
x_i [ -100, 100 ]x_i in [ -100, 100 ], for all
i=1,2i=1,2. The function has one global minimum at
f(x) = 0f(x) = 0 for x = [ 0, 0 ]x = [ 0, 0 ].