Create POS.py

Author: iscc7

POS.py

@@ -0,0 +1,67 @@
+from matplotlib import pyplot as plt
+from numpy import exp,sin,cos, array, square,sqrt,var,mean,linspace
+from random import random
+from time import clock
+
+def fun(x):
+    x = array(x)
+    return (sin(x+square(x*10)))/(sqrt(x+square(x)))
+
+
+def initial(size,down,up):
+    pops = []
+    for item in range(size):
+        a = down+random()*(up-down)
+        pops.append(a)
+    y_pops = fun(pops)
+    his_individual = pops
+    y_pops = y_pops.tolist()
+    y_pops_index = y_pops.index(max(y_pops))
+    his_social = pops[y_pops_index]
+    return pops,his_individual,his_social
+def pops_update(pops,w,v,c1,c2,his_individual,his_social,down,up):
+    for i in range(len(pops)):
+        v = w*v+c1*random()*(his_individual[i]-pops[i])+c2*random()*(his_social-pops[i])
+        pops[i] = pops[i]+v
+        if pops[i]>up:
+            pops[i] = up
+        if pops[i]<down:
+            pops[i] = down
+    return pops
+def his_update(pops,his_ind):
+    y_pops = fun(pops)
+    y_his_ind = fun(his_ind)
+    for i in range(len(pops)):
+        if y_his_ind[i]<y_pops[i]:
+            his_ind[i] = pops[i]
+
+    y_pops = y_pops.tolist()
+    y_pop_index = y_pops.index(max(y_pops))
+    his_soc = pops[y_pop_index]
+    return his_ind,his_soc
+
+if __name__ == '__main__':
+    bagin = clock()
+    up =0.4
+    down = 0.2
+    pop_size = 10
+    w = 0.1
+    v = 1
+    c1 = 2
+    c2 = 2
+    pops_0,his_individual,his_social = initial(pop_size,down,up)
+    plt.plot(pops_0,fun(pops_0),'r*')
+    pops_1 = pops_0
+    while var(pops_1)/mean(pops_1)>0.0001:
+        pops_1 = pops_update(pops_1,w,v,c1,c2,his_individual,his_social,down,up)
+        his_individual,his_social = his_update(pops_1,his_individual)
+
+    plt.plot(pops_1, fun(pops_1), 'k*')
+    end = clock()
+    print pops_1,'\n',var(pops_1),'\n',end-bagin
+
+    x = linspace(down,up,1000)
+    y =fun(x)
+    plt.plot(x,y,'b--')
+    plt.show()
+