def array2dist(values)
      values.map { |x, v| format('#%i %s', x, v) }.join(' ')
    end
def array2dist(values)
      values.map { |x, v| format('#%i %s', x, v) }.join(' ')
    end
rubocop:enable Metrics/AbcSize
 Turn an array of arrays into a the values part of a distribution
 @return [String]