Graph Laplacian

laplacian.js

function laplacian(G, N) {
  var L = new Array(N);
  for (var i = 0; i < N; i++) {
    var row = new Array(N);
    var node = G.nodes[i];
    for (var j = 0; j < N; j++) {
      if (i === j) {
        row[j] = node.edges.length;
      } else {
        row[j] = (node.edges.indexOf(j) === -1) ? -1 : 0;
      }
    }
    L[i] = row;
  }
  return L;
}