dstats.summary.histogram

[JackStouffer]

Histogram function would be very helpful. Bonus points if it has a overload that allows for explicitly setting the bins with an array/range.

[JackStouffer]

auto hist(Range)(Range data, uint bins) if (isForwardRange!Range)
{
    immutable minimum = data
        .save
        .reduce!min
        .floor
        .lround;
    immutable maximum = data
        .save
        .reduce!max
        .ceil
        .lround;
    immutable bin_width = (maximum - minimum) / bins;

    auto results = iota(0, bins + 1)
        .map!(a => tuple(double(0), minimum + (bin_width * a)))
        .array;

    foreach (item; data)
    {
        immutable bin = (lround(item) - minimum) / bin_width;
        results[bin][0]++;
    }

   return results;
}