YouPlot/lib/youplot/backends/processing.rb

# frozen_string_literal: true

module YouPlot
  # plotting functions.
  module Backends
    module Processing
      module_function

      def count_values(arr, tally: true, reverse: false)
        # tally was added in Ruby 2.7
        result = \
          if tally && Enumerable.method_defined?(:tally)
            arr.tally
          else
            # value_counts Enumerable::Statistics
            arr.value_counts(dropna: false)
          end

        # sorting
        result = result.sort do |a, b|
          # compare values
          r = b[1] <=> a[1]
          # If the values are the same, compare by name
          r = a[0] <=> b[0] if r.zero?
          r
        end

        # --reverse option
        result.reverse! if reverse

        # prepare for barplot
        result.transpose
      end
    end
  end
end