Markov Chain Generator

index.js

var numNodes = 20;
var roundNum = 100;
var a = [];
for (var i = 0; i < numNodes; ++i) {
  var connections = [];
  var sum = 0;
  for (var j = 0; j < numNodes; ++j) {
    var randNum = Math.random() / numNodes;
    // round the num
    randNum = Math.round(randNum * roundNum) / roundNum;
    connections[j] = randNum;
    sum += randNum;
  }
  // Fix the sum
  connections = connections.map(function (oldNum) {
    var newNum = oldNum * (1/sum);
    // round the num
    newNum = Math.round(newNum * roundNum) / roundNum;
    return newNum;
  });
  sum = connections.reduce(function (p, n) {
    return p + n;
  });
  // Fix the sum again
  connections[numNodes - 1] += 1 - sum;
  connections[numNodes - 1] = Math.round(connections[numNodes - 1] * roundNum) / roundNum;
  a[i] = connections;
}
console.log(JSON.stringify(a));