Benchmark: Randomly selecting between N maximal values and returning key in Ruby hash.

random_maxima.rb

Benchmark.bm do |x|
  
  types = {
    banana: 0.2,
    lemon: 0.4,
    orange: 0.4
  }
  
  x.report("select") do
    1.upto(10000) do 
      maxw = types.values.max
      selection = types.select { |i,j| j == maxw }.keys.sample
    end
  end
  
  x.report("group_by") do
    1.upto(10000) do 
      selection = types.group_by {|k, v| v}.max.last.sample.first
    end
  end
  
end

# Results on Ruby 1.9.3
#        user     system      total        real
# select  0.030000   0.000000   0.030000 (  0.032520)
# group_by  0.070000   0.000000   0.070000 (  0.072939)