thursday/thursday/external/evolopy/JAYA.py

119 lines
3.5 KiB
Python

""" JAYA Algorithm """
import random
import numpy
import math
from .solution import solution
import time
def JAYA(objf, lb, ub, dim, SearchAgents_no, Max_iter):
# Best and Worst position initialization
Best_pos = numpy.zeros(dim)
Best_score = float("inf")
Worst_pos = numpy.zeros(dim)
Worst_score = float(0)
fitness_matrix = numpy.zeros((SearchAgents_no))
if not isinstance(lb, list):
lb = [lb] * dim
if not isinstance(ub, list):
ub = [ub] * dim
# Initialize the positions of search agents
Positions = numpy.zeros((SearchAgents_no, dim))
for i in range(dim):
Positions[:, i] = (
numpy.random.uniform(0, 1, SearchAgents_no) * (ub[i] - lb[i]) + lb[i]
)
for i in range(0, SearchAgents_no):
# Return back the search agents that go beyond the boundaries of the search space
for j in range(dim):
Positions[i, j] = numpy.clip(Positions[i, j], lb[j], ub[j])
# Calculate objective function for each search agent
fitness = objf(Positions[i])
fitness_matrix[i] = fitness
if fitness < Best_score:
Best_score = fitness # Update Best_Score
Best_pos = Positions[i]
if fitness > Worst_score:
Worst_score = fitness # Update Worst_Score
Worst_pos = Positions[i]
Convergence_curve = numpy.zeros(Max_iter)
s = solution()
# Loop counter
print('JAYA is optimizing "' + objf.__name__ + '"')
timerStart = time.time()
s.startTime = time.strftime("%Y-%m-%d-%H-%M-%S")
# Main loop
for l in range(0, Max_iter):
# Update the Position of search agents
for i in range(0, SearchAgents_no):
New_Position = numpy.zeros(dim)
for j in range(0, dim):
# Update r1, r2
r1 = random.random()
r2 = random.random()
# JAYA Equation
New_Position[j] = (
Positions[i][j]
+ r1 * (Best_pos[j] - abs(Positions[i, j]))
- r2 * (Worst_pos[j] - abs(Positions[i, j]))
)
# checking if New_Position[j] lies in search space
if New_Position[j] > ub[j]:
New_Position[j] = ub[j]
if New_Position[j] < lb[j]:
New_Position[j] = lb[j]
new_fitness = objf(New_Position)
current_fit = fitness_matrix[i]
# replacing current element with new element if it has better fitness
if new_fitness < current_fit:
Positions[i] = New_Position
fitness_matrix[i] = new_fitness
# finding the best and worst element
for i in range(SearchAgents_no):
if fitness_matrix[i] < Best_score:
Best_score = fitness_matrix[i]
Best_pos = Positions[i, :].copy()
if fitness_matrix[i] > Worst_score:
Worst_score = fitness_matrix[i]
Worst_pos = Positions[i, :].copy()
Convergence_curve[l] = Best_score
if l % 1 == 0:
print(
["At iteration " + str(l) + " the best fitness is " + str(Best_score)]
)
timerEnd = time.time()
s.endTime = time.strftime("%Y-%m-%d-%H-%M-%S")
s.executionTime = timerEnd - timerStart
s.convergence = Convergence_curve
s.optimizer = "JAYA"
s.bestIndividual = Best_pos
s.objfname = objf.__name__
return s