This function is defined by

In dimension two and on it gives the Figure 1. With a lot of imagination, you can almost recognize the French Côte d’Azur on the south and the Mont Blanc as the highest summit. This function is interesting for testing the search of an extremum for the following reasons:

• there are as many local extrema we want, just by increasing x_max,
• there is just one global extrema,
• the solution can easily be directly computed.

In any dimension D, in the hypercube , the maximum is at the point  where x_s is the solution of

that is to say the point . The maximal value is then about .