This is an accelerated PSO (APSO), developed by Xin-She Yang in 2008. APSO does not use velocities or any inertia parameter.
A full program for solving nonlinear constrained optimization problem (welded beam design as an example) is provided, which can be extended to solve other continuous optimization problems.
Thank you very much for the codes. It is working quite well to my problem. However, I think there is a mistyping in the function "findrange". In this case, where we have "n=length(ns)", it should be "n=size(ns,1)".