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# how to solve Dijkstra algorithm in MATLAB?

Asked by Sivakumaran Chandrasekaran on 24 Aug 2012

I used the command “graphshortestpath” to solve “Dijkstra”. I am not getting the correct answer as the output is concentrating on the reduction of nodes alone. I need to follow the path of reduced distance(between 2 nodes) alone.

My coding is for 24 nodes.

```clc;
clear all;
close all;
W = [2.10 1.65 2.20 1.50 1.55 2 1.50 1.05 1.75 1.75 1.75 1 1 0.4 1.25 0.75 1.50 1.75 2 2 1.75 0.65 1.05 1.75 0.45 2.75 1.75 1.75 0.5 1.05 0.75 1 1.50 1.25 1 0.75 0.75 0.5 0.5 0.75 0.5];
DG = sparse([1 1 1 1 1 2 2 2 3 3 4 4 4 4 5 5 6 6 7 7 8 8 8 9 9 10 10 11 12 16 16 17 17 18 19 19 20 21 23 24 25],[2 3 4 16 19 5 6 17 6 7 7 8 12 24 9 18 9 10 10 11 7 22 23 10 25 13 14 13 21 2 17 5 18 15 4 20 12 22 11 3 14],W);
g=DG;
names=W;
h = view(biograph(DG,[],'ShowWeights','on'))
s=1;
d=input ('Enter the Destination node : ');
[dist,path,pred]=graphshortestpath(DG,s,d,'Directed',true,'method','Dijkstra');
set(h.Nodes(path),'Color',[1 0.4 0.4]);
edges = getedgesbynodeid(h,get(h.Nodes(path),'ID'));
set(edges,'LineColor',[1 0 0])
set(edges,'LineWidth',1.5)
```

For the path node 1- node10, manual output is 1-16-2-6-10 But, I got the output as 1-3-6-10.

## Products

Answer by Lucio Cetto on 24 Sep 2012

I get the distance of 1-16-2-6-10 to be 5.8, while 1-3-6-10 is 5.15. HTH

I am getting the same as previous comment above, there could be some mistake in manual solution that you attempted. Because even by looking up on your network its obvious that SP is 1-3-6-10.