fix the calculation of the plain bloomfilter's capacity

gmcabrita · Jul 13, 2018 · 06c6d25 · 06c6d25
1 parent 62bf7f3
commit 06c6d25
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Showing 2 changed files with 5 additions and 5 deletions.
diff --git a/lib/bloomex.ex b/lib/bloomex.ex
@@ -165,7 +165,7 @@ defmodule Bloomex do
 
     mb =
       case mode do
-        :size -> 1 + trunc(-log2(1 - :math.pow(1 - p, 1 / e)))
+        :size -> 1 + trunc(-log2(1 - :math.pow(1 - p, 1 / capacity)))
         :bits -> capacity
       end
 

diff --git a/test/bloomex_test.exs b/test/bloomex_test.exs
@@ -15,11 +15,11 @@ defmodule BloomexTest do
     bloom = Bloomex.plain(50, 0.10)
     assert Bloomex.member?(bloom, 5) == false
 
-    assert Bloomex.capacity(bloom) == 1
+    assert Bloomex.capacity(bloom) == 52
     assert Bloomex.size(bloom) == 0
 
     bloom = Bloomex.add(bloom, 2) |> Bloomex.add(3) |> Bloomex.add(2) |> Bloomex.add(10)
-    assert Bloomex.member?(bloom, 1) == true
+    assert Bloomex.member?(bloom, 10) == true
   end
 
   test "plain add" do
@@ -31,14 +31,14 @@ defmodule BloomexTest do
     bloom = Bloomex.scalable(6000, 0.001, 0.001, 3)
 
     bloom = Enum.reduce(1..10000, bloom, fn x, acc -> Bloomex.add(acc, x) end)
-    assert Bloomex.size(bloom) == 7025
+    assert Bloomex.size(bloom) == 9998
   end
 
   test "scalable force mb to be bigger than 16" do
     bloom = Bloomex.scalable(100, 0.1, 0.1, 3)
 
     bloom = Enum.reduce(1..90000, bloom, fn x, acc -> Bloomex.add(acc, x) end)
     assert Bloomex.member?(bloom, 1) == true
-    assert Bloomex.size(bloom) == 61993
+    assert Bloomex.size(bloom) == 80253
   end
 end