Sync

Task/Probabilistic-choice/Nimrod/probabilistic-choice.nimrod

@@ -0,0 +1,47 @@
+import tables, math, strutils, times
+
+const
+   num_trials = 1000000
+   precsn     = 6
+
+var start = cpuTime()
+
+var probs = initTable[string,float](16)
+probs.add("aleph",  1/5.0)
+probs.add("beth",   1/6.0)
+probs.add("gimel",  1/7.0)
+probs.add("daleth", 1/8.0)
+probs.add("he",     1/9.0)
+probs.add("waw",    1/10.0)
+probs.add("zayin",  1/11.0)
+probs.add("heth",   1759/27720)
+
+var samples = initTable[string,int](16)
+for i, j in pairs(probs):
+    samples.add(i,0)
+
+randomize()
+for i in 1 .. num_trials:
+    var z = random(1.0)
+
+    for j,k in pairs(probs):
+        if z < probs[j]:
+            samples[j] = samples[j] + 1
+            break
+        else:
+             z = z - probs[j]
+
+var s1, s2: float
+
+echo("Item  ","\t","Target  ","\t","Results  ","\t","Difference")
+echo("====  ","\t","======  ","\t","=======  ","\t","==========")
+for i, j in pairs(probs):
+    s1 += samples[i]/num_trials*100.0
+    s2 += probs[i]*100.0
+    echo( i,
+             "\t", formatFloat(probs[i],ffDecimal,precsn),
+             "\t", formatFloat(samples[i]/num_trials,ffDecimal,precsn),
+             "\t", formatFloat(100.0*(1.0-(samples[i]/num_trials)/probs[i]),ffDecimal,precsn),"%")
+echo("======","\t","======= ","\t","======== ")
+echo("Total:","\t",formatFloat(s2,ffDecimal,2),"  \t",formatFloat(s1,ffDecimal,2))
+echo("\n",formatFloat(cpuTime()-start,ffDecimal,2)," secs")

Task/Probabilistic-choice/Perl-6/probabilistic-choice.pl6

@@ -1,27 +1,19 @@
 constant TRIALS = 1e4;
 
-sub prob_choice_picker (%options is copy) {
-  my $n = 0;
-  $_ = ($n += $_) for values %options;
-  return sub {
-    my $r = rand;
-    (first { $r < .value }, %options).key;
-  };
-}
-
-my %ps = (
-  (map {$^w => 1/$^n}, (5 .. 11 Z <aleph beth gimel daleth he waw zayin>)),
-  heth => 0
-);
+my %ps = <aleph beth gimel daleth he waw zayin> Z=> 1 «/« (5 .. 11);
 %ps<heth> = 1 - [+] values %ps;
 
-&picker = prob_choice_picker %ps;
 my %results;
-++%results{picker} for ^TRIALS;
+for ^TRIALS {
+    %results{.key}++ given
+    first { .value > state $ = rand },
+    state % = %ps.keys Z=> [\+] %ps.values;
+}
 
 say 'Event   Occurred  Expected  Difference';
-for sort { .value }, %results {
+for sort *.value, %results {
+    my ($occurred, $expected) = .value/TRIALS, %ps{.key};
     printf "%-6s  %f  %f  %f\n",
-        .key, .value/TRIALS, %ps{.key},
-        abs( .value/TRIALS - %ps{.key} );
+        .key, $occurred, $expected,
+        abs( $occurred - $expected );
 }

Task/Probabilistic-choice/Ruby/probabilistic-choice.rb

@@ -1,4 +1,3 @@
-ordered_keys = ["aleph", "beth", "gimel", "daleth", "he", "waw", "zayin", "heth"]
 probabilities = {
   "aleph"  => 1/5.0,
   "beth"   => 1/6.0,
@@ -8,10 +7,11 @@ probabilities = {
   "waw"    => 1/10.0,
   "zayin"  => 1/11.0,
 }
-probabilities["heth"] = probabilities.each_value.inject(1) {|heth, value| heth -= value}
+probabilities["heth"] = 1.0 - probabilities.each_value.inject(:+)
+ordered_keys = probabilities.keys
 
-sums = {}
-ordered_keys.each.inject(0) do |sum, key|
+sum, sums = 0.0, {}
+ordered_keys.each do |key|
   sum += probabilities[key]
   sums[key] = sum
 end
@@ -29,7 +29,9 @@ samples.times do
   end
 end
 
-printf "%-6s  %-19s  %s\n", "key", "expected", "actual"
+puts  "key     expected    actual        diff"
 for k in ordered_keys
-  printf "%-6s  %.17f  %.6f\n", k, probabilities[k], Float(actual[k])/samples
+  act = Float(actual[k]) / samples
+  val = probabilities[k]
+  printf "%-8s%.8f  %.8f  %6.3f %%\n", k, val, act, 100*(act-val)/val
 end