% -----------------------------------------------------------------------------------------------------------
% Dung Beetle Optimizer: (DBO) (demo)
function [fMin , bestX, Convergence_curve ] = DBO(pop, M,c,d,dim,fobj )
P_percent = 0.2; % The population size of producers accounts for "P_percent" percent of the total population size
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
pNum = round( pop * P_percent ); % The population size of the producers
lb= c.*ones( 1,dim ); % Lower limit/bounds/ a vector
ub= d.*ones( 1,dim ); % Upper limit/bounds/ a vector
%Initialization
for i = 1 : pop
x( i, : ) = lb + (ub - lb) .* rand( 1, dim );
fit( i ) = fobj( x( i, : ) ) ;
end
pFit = fit;
pX = x;
XX=pX;
[ fMin, bestI ] = min( fit ); % fMin denotes the global optimum fitness value
bestX = x( bestI, : ); % bestX denotes the global optimum position corresponding to fMin
% Start updating the solutions.
for t = 1 : M
[fmax,B]=max(fit);
worse= x(B,:);
r2=rand(1);
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
for i = 1 : pNum
if(r2<0.8)
r1=rand(1);
a=rand(1,1);
if (a>0.1)
a=1;
else
a=-1;
end
x( i , : ) = pX( i , :)+0.2*abs(pX(i , : )-worse)+a*0.1*(XX( i , :)); % Equation (1)
else
aaa= randperm(180,1);
if ( aaa==0 ||aaa==90 ||aaa==180 )
x( i , : ) = pX( i , :);
end
theta= aaa*pi/180;
x( i , : ) = pX( i , :)+tan(theta).*abs(pX(i , : )-XX( i , :)); % Equation (2)
end
x( i , : ) = Bounds( x(i , : ), lb, ub );
fit( i ) = fobj( x(i , : ) );
end
[ fMMin, bestII ] = min( fit ); % fMin denotes the current optimum fitness value
bestXX = x( bestII, : ); % bestXX denotes the current optimum position
R=1-t/M; %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Xnew1 = bestXX.*(1-R);
Xnew2 =bestXX.*(1+R); %%% Equation (3)
Xnew1= Bounds( Xnew1, lb, ub );
Xnew2 = Bounds( Xnew2, lb, ub );
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Xnew11 = bestX.*(1-R);
Xnew22 =bestX.*(1+R); %%% Equation (5)
Xnew11= Bounds( Xnew11, lb, ub );
Xnew22 = Bounds( Xnew22, lb, ub );
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
for i = ( pNum + 1 ) :round(pop*0.45) % Equation (4)
x( i, : )=bestXX+((rand(1,dim)).*(pX( i , : )-Xnew1)+(rand(1,dim)).*(pX( i , : )-Xnew2));
x(i, : ) = Bounds( x(i, : ), Xnew1, Xnew2 );
fit(i ) = fobj( x(i,:) ) ;
end
for i = round(pop*0.45) +1: round(pop*0.75) % Equation (6)
x( i, : )=pX( i , : )+((randn(1)).*(pX( i , : )-Xnew11)+((rand(1,dim)).*(pX( i , : )-Xnew22)));
x(i, : ) = Bounds( x(i, : ),lb, ub);
fit(i ) = fobj( x(i,:) ) ;
end
for j = round(pop*0.75) +1 : pop % Equation (7)
x( j,: )= bestX/5+randn(1,dim).*((abs(( pX(j,: )-bestXX)))+(abs(( pX(j,: )-bestX))))./2;
x(j, : ) = Bounds( x(j, : ), lb, ub );
fit(j ) = fobj( x(j,:) ) ;
end
% Update the individual's best fitness vlaue and the global best fitness value
XX=pX;
for i = 1 : pop
if ( fit( i ) < pFit( i ) )
pFit( i ) = fit( i );
pX( i, : ) = x( i, : );
end
if( pFit( i ) < fMin )
% fMin= pFit( i );
fMin= pFit( i );
bestX = pX( i, : );
% a(i)=fMin;
end
end
Convergence_curve(t)=fMin;
disp(['第',num2str(t),'次DBO优化神经网络的误差为：',num2str(fMin)])
end
% Application of simple limits/bounds
function s = Bounds( s, Lb, Ub)
% Apply the lower bound vector
temp = s;
I = temp < Lb;
temp(I) = Lb(I);
% Apply the upper bound vector
J = temp > Ub;
temp(J) = Ub(J);
% Update this new move
s = temp;
function S = Boundss( SS, LLb, UUb)
% Apply the lower bound vector
temp = SS;
I = temp < LLb;
temp(I) = LLb(I);
% Apply the upper bound vector
J = temp > UUb;
temp(J) = UUb(J);
% Update this new move
S = temp;
%---------------------------------------------------------------------------------------------------------------------------
