In mathematical optimization, the Rastrigin function is a non-convex function used as a performance test problem for optimization algorithms.
It was first proposed in 1974 by Rastrigin[1] as a 2-dimensional function and has been generalized by Rudolph.
[2] The generalized version was popularized by Hoffmeister & Bäck[3] and Mühlenbein et al.[4] Finding the minimum of this function is a fairly difficult problem due to its large search space and its large number of local minima.
There are many extrema: Here are all the values at 0.5 interval listed for the 2D Rastrigin function with
: The abundance of local minima underlines the necessity of a global optimization algorithm when needing to find the global minimum.