histogram

In std/collections.

reduction fn histogram(self: Collection<Int>, width: Int) : SortedMap<Int, Int>
reduction fn histogram(self: Collection<Float>, width: Float) : SortedMap<Float, Int>

The number of occurrences in each bucket of width, keyed by the bucket's lower bound, the greatest multiple of width not above the value, in key order: [1, 5, 12, -3] | histogram(5) is SortedMap {-5: 1, 0: 1, 5: 1, 10: 1}. A width of zero or less is an evaluation error.