function [Xprey, Food_Score,CNVG] = HBA(objfunc, dim,lb,ub,tmax,N)
beta = 6; % the ability of HB to get the food Eq.(4)
C = 2; %constant in Eq. (3)
vec_flag=[1,-1];
%initialization
X=initialization(N,dim,ub,lb);
%Evaluation
fitness = fun_calcobjfunc(objfunc, X);
[GYbest, gbest] = min(fitness);
Xprey = X(gbest,:);
for t = 1:tmax
alpha=C*exp(-t/tmax); %density factor in Eq. (3)
I=Intensity(N,Xprey,X); %intensity in Eq. (2)
for i=1:N
r =rand();
F=vec_flag(floor(2*rand()+1));
for j=1:1:dim
di=((Xprey(j)-X(i,j)));
if r<.5
r3=rand; r4=rand; r5=rand;
Xnew(i,j)=Xprey(j) +F*beta*I(i)* Xprey(j)+F*r3*alpha*(di)*abs(cos(2*pi*r4)*(1-cos(2*pi*r5)));
else
r7=rand;
Xnew(i,j)=Xprey(j)+F*r7*alpha*di;
end
end
FU=Xnew(i,:)>ub;FL=Xnew(i,:)<lb;Xnew(i,:)=(Xnew(i,:).*(~(FU+FL)))+ub.*FU+lb.*FL;
tempFitness = fun_calcobjfunc(objfunc, Xnew(i,:));
if tempFitness<fitness(i)
fitness(i)=tempFitness;
X(i,:)= Xnew(i,:);
end
end
FU=X>ub;FL=X<lb;X=(X.*(~(FU+FL)))+ub.*FU+lb.*FL;
[Ybest,index] = min(fitness);
CNVG(t)=min(Ybest);
if Ybest<GYbest
GYbest=Ybest;
Xprey = X(index,:);
end
end
Food_Score = GYbest;
end
function Y = fun_calcobjfunc(func, X)
N = size(X,1);
for i = 1:N
Y(i) = func(X(i,:));
end
end
function I=Intensity(N,Xprey,X)
for i=1:N-1
di(i) =( norm((X(i,:)-Xprey+eps))).^2;
S(i)=( norm((X(i,:)-X(i+1,:)+eps))).^2;
end
di(N)=( norm((X(N,:)-Xprey+eps))).^2;
S(N)=( norm((X(N,:)-X(1,:)+eps))).^2;
for i=1:N
r2=rand;
I(i)=r2*S(i)/(4*pi*di(i));
end
end
function [X]=initialization(N,dim,up,down)
if size(up,2)==1
X=rand(N,dim).*(up-down)+down;
end
if size(up,2)>1
for i=1:dim
high=up(i);low=down(i);
X(:,i)=rand(N,1).*(high-low)+low;
end
end
end
