The Rosenbrock function, also called the valley or banana function, is a nonconvex optimization test problem. Its global minimum is f(x*) = 0 at (1, ..., 1), while the search landscape guides optimizers through a difficult valley. section 10.5
Key properties for optimization experiments include:
- Use n-dimensional inputs, commonly bounded by [-5, 10] or the narrower interval [-2.048, 2.048]. section 10.5
- Evaluate candidate solutions by their objective value; lower values indicate better solutions. section 10.5
- Use the function to expose how an optimizer explores a challenging nonconvex landscape. section 10.5
Minimizing the two-dimensional function with ABC
A small artificial bee colony experiment initializes six candidate positions in [-2.048, 2.048]. Their objective values range from 30.62 to 2,097.22. After neighborhood updates, the best candidate reaches 15.15, and fitness-proportionate selection gives it probability 0.49. A Python implementation with 50 bees and 1,000 iterations reports [0.99766117, 0.99542949] with fitness 6.50e-06. section 10.5
