How do I graph an adjacency list?

Hello everyone.

I have a graph being respresented as an Adjacency list:

AdjTable{1} = [2];
AdjTable{2} = [1, 3, 4];
AdjTable{3} = [2, 5];
AdjTable{4} = [2];
AdjTable{5} = [3];

G = AdjTable;

I was wondering how I can visually show this on a plot. I understand you're able to do this with Adjacency matrixers but can I stick to only using the lists?

Answer 1

[Walter Roberson]

Easiest way is to convert the adjacency list into an adjacency matrix. For each entry, set the matrix true at the row number corresponding to the cell index, and the column numbers given inside the entries. Then you can use graph() or digraph() and plot() the graph or digraph object.

(It can all be done in one line, but that is advanced MATLAB. Using sparse arrays helps.)

[RevengeOfTee]

Could you show an example of setting the matrix true.

[Walter Roberson]

adj(rowidx, AdjTable{rowidx}) =1;

[matlabpasta]

I am attempting to solve this problem and the line works properly by outputting a 4D double like so: adj(:,:,1,1), adj(:,:,2,1) ... adj(:,:5,2). It works but I am trying to get all the true results to output into a single array rather than 10 different arrays(for this specific example). I am not sure if what I said makes sense but I have posted the code I used below.

AT is the adjacency table and G1 == adj

ss = size(AT);

for ii = 1:ss(2)

rowidx = AT{ii};

G1(rowidx, AT{rowidx}) = 1;

end