LinAlg-NetworkAnalysis/main.m at main · jeffreyqdd/LinAlg-NetworkAnalysis · GitHub

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%%% set up command window
clear
clc
format short

%%% set up globals
TOTAL_NODES = 25;   % total number of nodes in this network
CONNECTIONS = [ ... % edges in this network (bi-directional connection)
    1, 2; ...
    2, 3; ...
    3, 4; ...
    4, 5; ...
    4, 6; ...
    6, 7; ...
    7, 8; ...
    8, 9; ...
    7, 10; ...
    10, 11; ...
    11, 12; ...
    12, 13; ...
    12, 14; ...
    14, 15; ...
    10, 16; ...
    16, 18; ...
    16, 17; ...
    17, 18; ...
    18, 19; ...
    18, 20; ...
    19, 20; ...
    20, 21; ...
    21, 22; ...
    22, 23; ...
    23, 24; ...
    23, 25; ...
];


%%% create laplacian matrix
laplacian = zeros(TOTAL_NODES, TOTAL_NODES);
[numR, numC] = size(CONNECTIONS);

for r=1:numR
    nodeA = CONNECTIONS(r,1);
    nodeB = CONNECTIONS(r,2);

    % Aij = Aji = -1 when i ~= j
    laplacian(nodeA, nodeB) = -1;
    laplacian(nodeB, nodeA) = -1;

    % update diagonal
    laplacian(nodeA, nodeA) = laplacian(nodeA, nodeA) + 1;
    laplacian(nodeB, nodeB) = laplacian(nodeB, nodeB) + 1;

end

%%% calculate eigen-values/vectors
[p,d] = eig(laplacian);

%%% display
disp(laplacian)
disp(p)
disp(d)