Round percents (lo-dash + coffee)

round_percents.coffee

  # Based on https://en.wikipedia.org/wiki/Largest_remainder_method
  roundPercents: (values) ->
    sum = 0
    sumNeeded = 100

    percents = _.map values, (value, i) ->
      quotient = _.floor(value)
      modulus = value % 1
      sum += quotient
      {
        quotient: quotient
        modulus: modulus
        originalIndex: i
      }

    if sum != sumNeeded
      percents = _.sortBy(percents, 'modulus').reverse()
      diff = sumNeeded - sum
      i = 0
      while i < diff
        percents[i].quotient += 1
        i += 1

    _.map(_.sortBy(percents, 'originalIndex'), 'quotient')