version 1.0.0.0 (2.57 KB) by
Dimas Aryo

Dijstra algorithm to solve shortest path problem.

This algorithm is to solve shortest path problem.

Usage

[cost rute] = dijkstra(graph, source, destination)

note : graph is matrix that represent the value of the edge. if node not connected with other node, value of the edge is 0.

example:

Finding shortest path form node 1 to node 7.

>> G = [0 3 9 0 0 0 0;

0 0 0 7 1 0 0;

0 2 0 7 0 0 0;

0 0 0 0 0 2 8;

0 0 4 5 0 9 0;

0 0 0 0 0 0 4;

0 0 0 0 0 0 0;

];

>> [cost rute] = dijkstra(G,1,7)

it will resulting

cost = 15

rute = [7 6 4 5 2 1]

Dimas Aryo (2021). Dijkstra Algorithm (https://www.mathworks.com/matlabcentral/fileexchange/36140-dijkstra-algorithm), MATLAB Central File Exchange. Retrieved .

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淼 程Rizki Ramadhanofir hadaddoes the algorithm assumes directed graph?

Elena FlorisHi, I tried this function with a matrix (16289X16289) that represent the values of the edge, specifically the distance between the edges, this values not are integer. I tried many example and the results of the function it is wrong. I don't understand what is the problem. Can you help me?

Chokri Khalfethi

i wanted to check your algorithm for stability, in a net of 3^7 possible combination has only failed in one.

the net is set up here (w is symmetric).

https://graphonline.ru/en/?graph=otGZuBAJBCVGNmhT

w=[ 0, 1, 0, 1, 0, 0, 0, 0, 0

1, 0, 1, 0, 1, 0, 0, 0, 0

0, 1, 0, 0, 0, 1, 0, 0, 0

1, 0, 0, 0, 1, 0, 1, 0, 0

0, 1, 0, 1, 0, 1, 0, 1, 0

0, 0, 1, 0, 1, 0, 0, 0, 1

0, 0, 0, 1, 0, 0, 0, 1, 0

0, 0, 0, 0, 1, 0, 1, 0, 1

0, 0, 0, 0, 0, 1, 0, 1, 0];

[~,p]=dijkstra(w,3,7)

p =

7 4 3 2 3

p is impossible

NardusThanks for your contribution. It it of great help. Congratulations.

Igor Sowasibabalo noludwwehi

i tried using the code and below is the error

Error using graph/subsref (line 7)

Indexing not supported.

Error in setupgraph (line 6)

if G(i,j)==0

Error in dijkstra (line 27)

A = setupgraph(A,inf,1);

Error in dijskra (line 23)

[cost rute]=dijkstra(G,13,2);

wang yanikwang yanik有中文交流一下的么？

Shaaib Najigreat code

can i use it to perfume bellman ford algorithm ?

what changes i have to make to accomplish that

Harry MitchellGood job!

Does this work for nodes where the edge weight is different depending on the direction that is taken?

matteo bartolonibig Albert i love you!!!!

Mendipeijin wuZHIHONG NGHi,

When i try to test run the program, it says Dijkstra algorithm requires more input arguments to run. :(

Zelong Shaovery good work,Thank you.

Caio Bastosyang LiAlbert Carfax --> Thanks for your advice and it solve the problem (passing node 1).

Rofi SRaqsa khanHi,

I am currently using this code in my research and it works perfectly fine for the small matrix but when i used this code to find the shortest path in large network which contains 3-4 lac nodes, Matlab gives me error of out of memory to create such a big matrix G. Please help me if you have any solution to this problem. Thanks

GISTAlbert Carfax --> Thank you!!

GISTKristian TakacHi,

Could you please tell me if it is possible to rewrite this algorithm to a form which will work with negative, respectively non-positive paths as well?

Thank you!

Miguel RuizIf dijkstra(G,1,2) = 3, how come dijkstra(G,2,1) = inf ?

Claire Wongwhy it cannot define the A.

>> dijkstra(A, s, d)

Undefined function or variable 'A'.

Albert CarfaxI found the error. To summarize what I've read of previous comments and confirmed myself, the code returns an incorrect route whenever the path passes through node one. This is because the code reorders the graph so that the source is node 1 and what was previously node 1 is now given the index that the source had previously (line 31: A=exchangenode(A,1,s);). When outputting the route, however, the indecies are not switched back properly. The index of the source is switched back (line 6 of linedijkstra: L=[L s];), but not the node was in the node 1 slot and got bumped out. Thus the route, if it passes through the original node one, will look like it passes through the source node and then still ends up at the source node.

You can fix the problem by either always arranging your graph so that the the source is node 1 or make the following substitution in listdijkstra.m:

Old code:

L=[L W(index2,1)];

New code:

if W(index2,1)==s

L = [L 1];

else

L=[L W(index2,1)];

end

flyingpigKhang NguyenIn listdijkstra, line 6, instead of having L=[L s], replace it with L=[s L]. That should solve the problem.

MoysesDutraThis code have one problem when route pass on first node (node number 1)

I'm Still looking for this mistake on code to correct it.

MoysesDutraVery good.

Works perfectly in our problem.

Thanks a lot.

David Molonyhanyu liuseful

Nikos BousiosPalmer AnisiThere is a bug in this code. Node 1 is usually replaced by node 4 for paths containing node 1

Falk LiederHarryShunbo LeiI recently find a bug of this code. If the path contain node 1, it generally will be replaced by the source node number.

aqeel lamiaqeel lamiit works great and thanks

RonanCould you please explain how you are defining nodes. It is not clear at all what how the source node and destination node are chosen and how the route relates to the start and end node?

Sara BaldwinHello I tried using this function but I am having trouble....In my matrix I have whole numbers but the matrix is a double (not sure why) and this algorithm is not working :(

Paul yangit works great! is there a version that provides all paths, rather than just the shortest path?

Martindoes anyone have the comments for this code. It works perfectly but i would like to understand the role of each function

CosyHi there,

what is wrong with this example:

G = [ 0 1 2;

1 0 0;

2 0 0 ]

dijkstra(G,2,3);

result: [3 2 2]

Can you help me?

PS: I see that Gautam Marwaha had the same problem. :(

Gautam MarwahaThis code mostly works fine but fails for a few cases:

G = [0 1 1 1 1 0 0;

1 0 0 1 0 1 0;

1 0 0 1 0 1 1;

1 1 1 0 1 0 0;

1 0 0 1 0 0 1;

0 1 1 0 0 0 1;

0 0 1 0 1 1 0];

dijkstra(G,3,5) yields [5 3 3] or [3 3 5]. Any ideas why this happens?

Alex Georgeany idea on how this works?

taewoo!!

Poonamgood algo..

MatthiasIt worked for my purpose! Thanks for it. 4 of 5 because i haven't tested it in extreme situations. Very well!!!