PSO

sir

I am dealing with the PSO algorithm given in the matlab file exchange (i.e)Pso.m .In that i have changed the velocity equation to get Time varying acceleration factors as

c1i=c2f=2.5;c1f=c2i=0.5;
ac1=(c1f-c1i)*(i/me)+C1i;
ac2=(c2f-c2i)*(i/me)+c2i;

now i have the variable acceleration coeffiecients and the velocity eqn is

v(i+1)=w(i)*v(i)+ac1*rand*(pbest(i)-x(i))+ac2*rand*(gbest(i)-x(i));
x(i+1)=x(i)+v(i+1)

now when i run with this it is giving different answers each time i run it. Plz help me such that I get the same answer whenever I did it.

Answer 1

[Walter Roberson]

You have rand() in your code. Of course you are going to get different answers each time you run it.

The work-around is to re-seed the random number generator to a constant value before running the code. The easiest method of reseeding the random number generator depends upon your MATLAB version.