How to calculate mean, median, mode and range from a set of numbers

Question

Are there any functions (as part of a math library) which will calculate mean, median, mode and range from a set of numbers.

Answer 1

If you only care about unimodal distributions, consider sth. like this.

public static Optional<Integer> mode(Stream<Integer> stream) {
    Map<Integer, Long> frequencies = stream
        .collect(Collectors.groupingBy(Function.identity(), Collectors.counting()));

    return frequencies.entrySet().stream()
        .max(Comparator.comparingLong(Map.Entry::getValue))
        .map(Map.Entry::getKey);
}