%?Usage:?bat_algorithm（[20?0.25?0.5]）;?????????????????????%

function?[bestfminN_iter]=Abat_algorithm（para）
%?Display?help
?help?bat_algorithm.m

%?Default?parameters
if?nargin<1??para=[10?0.25?0.5?0.8?0.6];?end
n=para（1）;??????%?Population?size?typically?10?to?25
A=para（2）;??????%?Loudness??（constant?or?decreasing）
r=para（3）;?
wmax=para（4）;
wmin=para（5）;
%?Pulse?rate?（constant?or?decreasing）
%?This?frequency?range?determines?the?scalings
Qmin=0;?????????%?Frequency?minimum
Qmax=2;?????????%?Frequency?maximum
%?Iteration?parameters
tol=10^（-5）;????%?Stop?tolerance
N_iter=0;???????%?Total?number?of?function?evaluations
%?Dimension?of?the?search?variables
d=5;
%?Initial?arrays
Q=zeros（n1）;???%?Frequency
v=zeros（nd）;???%?Velocities
%?Initialize?the?population/solutions
for?i=1:n
??Sol（i:）=randn（1d）;
??Fitness（i）=Fun（Sol（i:））;
end
%?Find?the?current?best
[fminI]=min（Fitness）;
best=Sol（I:）;


%?======================================================??%
%?Note:?As?this?is?a?demo?here?we?did?not?implement?the??%
%?reduction?of?loudness?and?increase?of?emission?rates.???%
%?Interested?readers?can?do?some?parametric?studies???????%
%?and?also?implementation?various?changes?of?A?and?r?etc??%
%?======================================================??%

%?Start?the?iterations?--?Bat?Algorithm
while?（fmin>tol）
?????for?i=1;n
????????fv（i）=?Fitness（i）;
????????????????end
????????favg=sum（fv）/n;
????????for?i=1;n
????????????if?fv（i）<=favg
????????????????w=wmin+（fv（i）-fmin）*（wmax-wmin）/（favg-fmin）;
????????????else
????????????????w=wmax;
????????????end
??????????Q（i）=Qmin+（Qmin-Qmax）*rand;
??????????v（i:）=w*v（i:）+（Sol（i:）-best）*Q（i）;
??????????S（i:）=Sol（i:）+v（i:）;
??????????%?Pulse?rate
??????????if?rand>r
??????????????S（i:）=best+0.01*randn（1d）;
??????????end

?????%?Evaluate?new?solutions
???????????Fnew=Fun（S（i:））;
?????%?If?the?solution?improves?or?not?too?loudness
???????????if?（Fnew<=Fitness（i））?&?（rand????????????????Sol（i:）=S（i:）;
????????????????Fitness（i）=Fnew;
???????????end
??????????%?Update?the?current?best
??????????if?Fnew<=fmin
????????????????best=S（i:）;
????????????????fmin=Fnew;
??????????end
?????end
??????????N_iter=N_iter+n;
end
plot（Fitness）?
%?Output/display
disp（[‘Number?of?evaluations:?‘num2str（N_iter）]）;
disp（[‘?fmin=‘num2str（fmin）]）;
disp（[‘Best?=‘num2str（best）]）;


function?z=Fun（u）
z=（1-u（1））^2+100*（u（2）-u（1）^2）^2+（1-u（3））^2+（u（4）-2）^2+（u（5）-0.4）^2;

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????2533??2018-05-21?18:52??Abat_algorithm.m