code: function normalizeProbs(arr) {
      var probs = [];
      var sum = 0.0;
      for (var i=0; i < arr.length; i++) {
        probs[i] = arr[i] + 0.001
        sum += probs[i]
      }
      for (var i=0; i < arr.length; i++) {
        probs[i] = probs[i] / sum;
      }
      return probs;
    }
docs: Normalizes an array of values such that the elements sum to 1.0. Note that
  0.001 is added to every value to avoid 0.0 probabilities. This adjustment
  helps with visualization downstream.
  @param {Array} arr Array of probabilities.
  @returns {Array} Normalized probailities.