median function

double? median(Iterable<num> values)

Returns the median of values, or null if the collection is empty.

For an even count, returns the average of the two middle values. Does not mutate the caller's input.

Example:

median([3, 1, 2]); // 2.0
median([4, 1, 2, 3]); // 2.5

Implementation

double? median(Iterable<num> values) {
  // ignore: saropa_lints/avoid_large_list_copy -- needs an independent copy to sort without mutating the caller's input
  final List<double> list = values.map((num n) => n.toDouble()).toList()..sort();
  if (list.isEmpty) return null;
  final int mid = list.length ~/ 2;
  if (list.length.isOdd) return list[mid];
  return (list[mid - 1] + list[mid]) / 2;
}