if i have an equation like $$f_n = x + y + z + a + b$$ and each variable has a discrete answer like $a = 0, 1 , 3$ . $b = 2 ,4,5$ etc. i want to find the global optimum minimization point. I used Ant colony optimization (ACO) to solve the equation but i am stuck in the heuristic information and how to compute these parameters, as I saw in the traveling sale's man problem eta = one over distance between two cities. But here there is no relation between $x$ and $y$ .
Second i want to make sure that when computing $\delta_\tau$ pheromone updating trail , its equal to $$f_n(\text{best answer in iteration k})\over f_n(\text{worth answer in iteration k})$$ as i saw another equations in papers and got distracted. I built a matlab model but it didn't give me the optimum point at each run time . Thank you