/Sine-Cosine-Algorithm

Primary LanguagePython

Sine Cosine Algorithm

Reference: Mirjalili S. SCA: A Sine Cosine Algorithm for solving optimization problems[J]. Knowledge-Based Systems, 2016, 96.
Variables Meaning
pop The number of candidates
iter The number of iterations
lb The lower bound (list)
ub The upper bound (list)
pos The position of all candidates (list)
score The score of all candidates (list)
dim Dimension
gbest The score of the global best candidate
gbest_pos The position of the global best candidate (list)
seed_pos The position of the seeds of the ith candidate (list)
seed_score The score of the seeds of the ith candidate (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
    pop = 30
    iter = 1000
    lb = [0, 0, 10, 10]
    ub = [99, 99, 200, 200]
    print(main(pop, iter, lb, ub))
Output:

The SCA converges at its 957-th iteration, and the global best value is 9590.464425690781.

{
    'best score': 9590.464425690781, 
    'best solution': [1.457576369166947, 0.6612071818606331, 68.48174413611495, 17.286314289498986], 
    'convergence iteration': 957
}