class RBench::Summary

def run
  # maybe add convenience-method to group to. group == runner really.
  items = (@group ? @group.items & @runner.reports : @runner.reports)
  
  rows = items.map{|item| item.cells.values_at(*@runner.columns.map{|c|c.name}) }
  rows = rows.pop.zip(*rows)
  @runner.columns.each_with_index do |c,i|
    if c.compare
      value,comparisons = 0,0
      items.each do |item|
        v1,v2 = *item.cells.values_at(*c.compare)
        if v1.kind_of?(Numeric) && v2.kind_of?(Numeric) && v1 != 0 && v2 != 0
          value += v1 / v2
          comparisons += 1
        end
      end
      @cells[c.name] = [value,comparisons] if comparisons > 0
    elsif c.name != :times
      @cells[c.name] = rows[i].compact.select{|r| r.kind_of?(Numeric)}.inject(0){|tot,v| tot += v.to_f }
    end
  end
  
  puts to_s
end