/Enhanced-Self-adaptive-Global-best-Harmony-Search

Primary LanguagePython

Enhanced Self-adaptive Global-best Harmony Search

Reference: Kaiping Luo, Jie Ma, Qiuhong Zhao. Enhanced self-adaptive global-best harmony search without any extra statistic and external archive. Information Sciences, 2019. 482: 228-247.
Variables Meaning
hms Harmony memory size
ni The number of improvisations (iterations)
hmcr Harmony memory consideration rate
par Pitch adjustment rate
bw Bandwidth
lb The lower bound (list)
ub The upper bound (list)
pos The set of harmonies (list)
score The score of harmonies (list)
dim Dimension
gbest The score of the global best harmony
gbest_pos The position of the global best harmony (list)
iter_best The global best score of each iteration (list)
con_iter The last iteration number when "gbest" is updated

Test problem: Pressure vessel design

$$ \begin{align} &\text{min}\ f(x)=0.6224x_1x_3x_4+1.7781x_2x_3^2+3.1661x_1^2x_4+19.84x_1^2x_3,\\ &\text{s.t.} \\ &-x_1+0.0193x_3\leq0,\\ &-x_3+0.0095x_3\leq0,\\ &-\pi x_3^2x_4-\frac{4}{3}\pi x_3^3+1296000\leq0,\\ &x_4-240\leq0,\\ &0\leq x_1\leq99,\\ &0\leq x_2 \leq99,\\ &10\leq x_3 \leq 200,\\ &10\leq x_4 \leq 200. \end{align} $$

Example

if __name__ == '__main__':
    # Parameter settings
    hms = 10
    lb = [0, 0, 10, 10]
    ub = [99, 99, 200, 200]
    ni = 10000 * len(lb)
    print(main(hms, ni, lb, ub))
Output:

The ESGHS converges at its 14,294-th iteration, and the global best value is 8050.914044830637.

{
    'best score': 8050.914044830637, 
    'best solution': [1.3005502310626382, 0.6428626530744853, 67.38602233485172, 10.000000182456352], 
    'convergence iteration': 14294
}