Random Path Generation between source node and destination node

Hello everyone,

I have got Implementation Idea . Can anyone help me to write code.

Suppose i have 5 node network. So, i have 5*5 matrix. My Source node=1 and Destination node=2 and i want to send f=9 units of data.

Rows show my source nodes and columns show my destination nodes,

What i am thinking-Implementation Idea-- 1. Create 5*5 zero matrix. Go to S =1 row.

2. I will have 4 positions available 2,3,4,5 to assign f=9.

3. Suppose 9 is assigned to 5.

4. Then i will go to row 5. next i have positions available 2,3,4.

5. I will go like this until until f=9 goes to position 2.

My outcome should be like=

     0     0     0     0     9
     0     0     0     0     0
     0     0     0     0     0
     0     9     0     0     0
     0     0     0     9     0

So, my path is 1 to 5 to 4 to 2.

Another example---

     0     0     0     0     9
     0     0     0     0     0
     0     9     0     0     0
     0     0     0     0     0
     0     0     9     0     0

My path is 1 to 5 to 3 to 2.

Answer 1

[Geoff Hayes]

Reshdev - you can try something like the following to create a random path between a source and a destination node.

function [randPath,randPerm] = createRandomPath(source,destination,weight,n)

 % initialize the path matrix
 randPath = zeros(n,n);

 % initialize the available nodes array
 availNodes = (1:1:n)';

 if 0<source && source<=n && 0<destination && destination<=n
    % remove the source node from the available nodes array
    availNodes(source) = [];

    % create a random permutation given the remaining nodes
    randPermIdcs = randperm(n-1)';

    % the indices define the path to take from node to node
    randPerm     = availNodes(randPermIdcs);

    % clip the random permuation given the destination
    destIdx = find(randPerm==destination);
    randPerm(destIdx+1:end) = [];

    % update the random path matrix
    linIdcs = sub2ind(size(randPath),[source;randPerm(1:end-1)],randPerm);
    randPath(linIdcs) = weight;

 end

The only randomness is in choosing the indices of the available nodes array which we then map back to the available nodes. Any node after the destination node is removed from that random permeation, after which we update the random path. For example,

 >> [randPath,randPerm] = createRandomPath(1,2,9,5)

 randPath =

     0     0     0     0     9
     0     0     0     0     0
     0     0     0     0     0
     0     9     0     0     0
     0     0     0     9     0

 randPerm =

     5
     4
     2

The randPerm output is the random permutation (that was generated) and the randPath is the path matrix given the source, destination, and random (path) permutation. In the above, we start at the source 1, move to 5, move to 4, and end at 2.