diff --git a/plugins/poll/assets/javascripts/lib/even-round.js.es6 b/plugins/poll/assets/javascripts/lib/even-round.js.es6 index 0395f1f16a6..5446c874c58 100644 --- a/plugins/poll/assets/javascripts/lib/even-round.js.es6 +++ b/plugins/poll/assets/javascripts/lib/even-round.js.es6 @@ -1,17 +1,29 @@ -// stolen from http://stackoverflow.com/a/13484088/11983 +// works as described on http://stackoverflow.com/a/13483710 function sumsUpTo100(percentages) { return percentages.map(p => Math.floor(p)).reduce((a, b) => a + b) === 100; } export default (percentages) => { - const sumOfDecimals = Math.ceil(percentages.map(a => a % 1).reduce((a, b) => a + b)); - // compensate error by adding 1 to the first n "non-zero" items - for (let i = 0, max = percentages.length; i < sumOfDecimals && i < max; i++) { - if (percentages[i] > 0) { - percentages[i] = ++percentages[i]; - // quit early when there is a rounding issue - if (sumsUpTo100(percentages)) break; + var decimals = percentages.map(a => a % 1); + const sumOfDecimals = Math.ceil(decimals.reduce((a, b) => a + b)); + // compensate error by adding 1 to n items with the greatest decimal part + for (let i = 0, max = decimals.length; i < sumOfDecimals && i < max; i++) { + // find the greatest item in the decimals array, set it to 0, + // and increase the corresponding item in the percentages array by 1 + let greatest = 0; + let index = 0; + for (let j=0; j < decimals.length; j++) { + if (decimals[j] > greatest) { + index = j; + greatest = decimals[j]; + } } + ++percentages[index]; + decimals[index] = 0; + // quit early when there is a rounding issue + if (sumsUpTo100(percentages)) break; } + return percentages.map(p => Math.floor(p)); }; +