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.

utils/hyperloglog/hll-gnuplot-graph.rb

@@ -10,7 +10,7 @@ require 'redis'
 require 'digest/sha1'
 
 # Generate an array of [cardinality,relative_error] pairs
-# in the 0 - max range with step of 1000*step.
+# 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
@@ -22,16 +22,15 @@ 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 {
-            elements = []
-            1000.times {
-                ele = Digest::SHA1.hexdigest(i.to_s+seed.to_s)
-                elements << ele
-                i += 1
-            }
-            r.pfadd('hll',*elements)
+            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
@@ -40,11 +39,12 @@ def run_experiment(r,seed,max,step)
     samples
 end
 
-def filter_samples(numsets,filter)
+def filter_samples(numsets,max,step,filter)
     r = Redis.new
     dataset = {}
     (0...numsets).each{|i|
-        dataset[i] = run_experiment(r,i,100000,1)
+        dataset[i] = run_experiment(r,i,max,step)
+        STDERR.puts "Set #{i}"
     }
     dataset[0].each_with_index{|ele,index|
         if filter == :max
@@ -62,6 +62,14 @@ def filter_samples(numsets,filter)
             }
             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]
@@ -73,6 +81,7 @@ def filter_samples(numsets,filter)
     }
 end
 
-filter_samples(100,:all)
-#filter_samples(100,:max)
-#filter_samples(100,:avg)
+filter_samples(100,100000,1000,:absavg)
+#filter_samples(100,1000,10,:all)
+#filter_samples(100,10000,1000,:max)
+#filter_samples(100,10000,1000,:avg)