redis/utils/hyperloglog/hll-gnuplot-graph.rb
antirez cf34507b87 hll-gnuplot-graph.rb improved with new filter.
The function to generate graphs is also more flexible as now includes
step and max value. The step of the samples generation function is no
longer limited to min step of 1000.
2014-04-02 12:30:11 +02:00

88 lines
2.5 KiB
Ruby

# hll-err.rb - Copyright (C) 2014 Salvatore Sanfilippo
# BSD license, See the COPYING file for more information.
#
# This program is suited to output average and maximum errors of
# the Redis HyperLogLog implementation in a format suitable to print
# graphs using gnuplot.
require 'rubygems'
require 'redis'
require 'digest/sha1'
# Generate an array of [cardinality,relative_error] pairs
# in the 0 - max range, with the specified step.
#
# 'r' is the Redis object used to perform the queries.
# 'seed' must be different every time you want a test performed
# with a different set. The function guarantees that if 'seed' is the
# same, exactly the same dataset is used, and when it is different,
# a totally unrelated different data set is used (without any common
# element in practice).
def run_experiment(r,seed,max,step)
r.del('hll')
i = 0
samples = []
step = 1000 if step > 1000
while i < max do
elements = []
step.times {
ele = Digest::SHA1.hexdigest(i.to_s+seed.to_s)
elements << ele
i += 1
}
r.pfadd('hll',*elements)
approx = r.pfcount('hll')
err = approx-i
rel_err = 100.to_f*err/i
samples << [i,rel_err]
end
samples
end
def filter_samples(numsets,max,step,filter)
r = Redis.new
dataset = {}
(0...numsets).each{|i|
dataset[i] = run_experiment(r,i,max,step)
STDERR.puts "Set #{i}"
}
dataset[0].each_with_index{|ele,index|
if filter == :max
card=ele[0]
err=ele[1].abs
(1...numsets).each{|i|
err = dataset[i][index][1] if err < dataset[i][index][1]
}
puts "#{card} #{err}"
elsif filter == :avg
card=ele[0]
err = 0
(0...numsets).each{|i|
err += dataset[i][index][1]
}
err /= numsets
puts "#{card} #{err}"
elsif filter == :absavg
card=ele[0]
err = 0
(0...numsets).each{|i|
err += dataset[i][index][1].abs
}
err /= numsets
puts "#{card} #{err}"
elsif filter == :all
(0...numsets).each{|i|
card,err = dataset[i][index]
puts "#{card} #{err}"
}
else
raise "Unknown filter #{filter}"
end
}
end
filter_samples(100,100000,1000,:absavg)
#filter_samples(100,1000,10,:all)
#filter_samples(100,10000,1000,:max)
#filter_samples(100,10000,1000,:avg)