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## Bat algorithm (demo)

version 1.0.0.0 (2.9 KB) by
This is a demo for Bat Algorithm, developed by Xin-She Yang (2010).

Updated 20 Jul 2012

This is a short demo for the popular, nature-inspired/metaheuristic,
bat algorithm (BA), which can deal with nonlinear, global optimization problems.
Bat algorithm has the advantages of simplicity, flexility and stability.
It can also automatically switch from global exploration to
local exploitation by fine-tuning its parameters: A and r.

http://arxiv.org/abs/1004.4170

### Cite As

Xin-She Yang (2021). Bat algorithm (demo) (https://www.mathworks.com/matlabcentral/fileexchange/37582-bat-algorithm-demo), MATLAB Central File Exchange. Retrieved .

Taha Butt

Hello Yang, in your file what does rand(1,d) implies? i think it is the population that you set to 1 in n=input(1) . you told in the code to write the population between 20 to 40 but, why you didnt write it by yourself? i am trying yo write the population 20 instead of 1 but it would not let me.

Haydar Khayou

Thank you very much Dr. Yang, but I've been trying to write a Matlab code following the steps provided by your book, and I have found that the rate of pulse emission should increase with iterations, but it's decreasing in the code!!!
another important thing is why to link the choosing of new better solution with a decreasing probability!!

djim djim

hello,
The BAT algorithm Source Code , do not converge for any benchMark function!!

djim djim

wenbin Leon

jianlu hu

Mohamed Kamel

Abhishek Gupta

The complete implementation of BAT algorithm is available at https://in.mathworks.com/matlabcentral/fileexchange/68981-bat-optimization-algorithm

SAID ZAKARIA SAID

Hello Prof Xin-She Yang
How to hybridize BAT algorithm with Moth-Flame Optimization Algorithm if you have them in different scripts.

email: djiddosaid@gmail.com
Thank you so much

dear proffesor,
I am very interested in bat algorithm and decided to use it in my final year project for improvement in global optimazation problems.
can you send the bat algorithm code to me so that i could study it. Thank you.

upendra bajpai

please someone explain why we have chosen here dimension d & what it indicates.

Pranay Rayana

hello,
I did not understand this code. Can't we create an environment and view the shortest path like in Probabilistic Road Map (PRM)?
And what does the dimension mean in this code?

mingzhu zhang

if (Fnew<=Fitness(i)) & (rand<A) ,
Sol(i,:)=S(i,:);
Fitness(i)=Fnew
end
Why accept a better solution with a certain probability? And This probability becomes smaller and smaller as the number of iterations increases

wanghu wanghu

Thank you for your share of Dr. Yang.

Yang Li

if (rand < Ai & f(xi) < f(x))
Accept the new solutions
Increase ri and reduce Ai
end if
in the article of Dr. Yang, but the code is different. I need a great code of Matlab . Thank you! 263211434@qq.com

Luis Lopez

jkthink

I noticed that problem as well. Your solution seems to work, though it would have been great if Dr. Yang could provide with a formal solution. 835441346@qq.com

Mahima j

I want a solution matlab code modified bat algorithm

asharani belanke

Hello..can u plz help to write a code for minimize the total cost.actually my Ain is allocation of battery in microgrid.and I am extremely new in MATLAB.

ronit agarwal

i want bat algorithm and code for clustering in java.........

Dear Prof

Im a maths student an I have found Bat algorithm to interesting would like so much to know if the Bat Inspired algorithm can be of any use in the fields of Electrical distribution and Transmission.

Email:2016sors@gmail.com

zhen li

dear prof
I am very interested in bat algorithm.
can you send the bat algorithm code to me?
e-mail
zhenli_ysu@126.com

thank you

dalia elkashef

dear prof

can you help me with chaotic bat algorithm code ??
e-mail
eng.daliaarafa@gmail.com

yi'xing wang

payam baban

Shramana GS

I Have a Question. Everytime I run this algorithm, I get different sets of solutions every time. Why is it so? Shouldn't there be a unique solution for a given problem? Plz Help.

Sindhuja J

baibhav bishal

karim

Hello
@ Eric : In the article published by Dr. Yang, he did not specify that “epsilon” must be a uniform random number.

Comparing the proposed demo and the pseudo-code presented in the article of Dr. Yang, I noticed this:
In the article: if (rand < Ai & f(xi) < f(x*)) and x* is the current global best location (solution) which is located after comparing all the solutions among all the n bats. But, in the demo,
if (Fnew<=Fitness(i)) & (rand<A),
Sol(i,:)=S(i,:);
Fitness(i)=Fnew;
end
I understand from this that for each bat, we do a comparaison between the new calculated fitness values against the previous one, not against the global best. Then, each bat memorises his "individual" best location and update it according to the condition mentionned above. I hope that i will have clarification about this.

Eric

There are three discrepancies in this code (compared to the published algorithm)

1. Line 79
Q(i)=Qmin+(Qmin-Qmax)*rand;

should be replaced with
Q(i)=Qmin+(Qmax-Qmin)*rand;

2. Similar to what @Frank said
Line 83
Sol(i,:)=simplebounds(Sol(i,:),Lb,Ub);

should be replaced with
S(i,:)=simplebounds(S(i,:),Lb,Ub);
and moved to Line 89 (*before* %Evaluate Evaluate new solutions)

3. Line 87
S(i,:)=best+0.001*randn(1,d);

The 2010 paper "A New Metaheuristic Bat-Inspired Algorithm" seems to suggest that 0.001 should be the variable "A" and that randn(1,d) should actually be 1-2*rand(1,d)... that is a uniformly distributed random number bounded by [-1,1].

leoc

@Frank,

I noticed that problem as well. Your solution seems to work, though it would have been great if Dr. Yang could provide with a formal solution.

Amon

Hello
I have my Objective function and constraint, anyone can help me to guide me on how implement it.
Actually mu purpose is reduce electric distribution loss.

acharab

It is good.

Frank

Would this line of code in bat_algorithm.m:

% Apply simple bounds/limits
Sol(i,:)=simplebounds(Sol(i,:),Lb,Ub);

be moved to just above the line of
% Evaluate new solutions

and be modified to:
S(i,:)=simplebounds(S(i,:),Lb,Ub);

so that we may not have solutions outside the lower and upper bound?

hui

Easy to understand...

Al Algo

Very easy to understand but works magic.

peng

It is easy to understand, and it works magic. Excellent!

win

simple and easy of use.... thanks

sehrish

I am interest in your optimization algorithm. May i know is there a 'train' function coded because I would want to use it to train neural network.
Thank you.

sehrish

Hi plz anyone can guide how to train Neural Network using Bat algorithm????

d g

also how to get graphs for bat algorithm..?

d g

hey i want to compare cuckoo search and bat algorithm.. can you tell me on what parameters should i compare them..

teroy tman

It is very good.

Q Q

It is easy to understand, and it works magic. Excellent!

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