September Morn Update

Task/Monte-Carlo-methods/Clojure/monte-carlo-methods-2.clj

@@ -0,0 +1,9 @@
+(defn experiment
+  []
+  (if (<= (+ (Math/pow (rand) 2) (Math/pow (rand) 2)) 1) 1 0))
+
+(defn pi-estimate
+  [n]
+  (* 4 (float (/ (reduce + (take n (repeatedly experiment))) n))))
+
+(pi-estimate 10000)

Task/Monte-Carlo-methods/Erlang/monte-carlo-methods-1.erl

@@ -0,0 +1,17 @@
+-module(monte).
+-export([main/1]).
+
+monte(N)->
+    monte(N,0,0).
+
+monte(0,InCircle,NumPoints) ->
+    4 * InCircle / NumPoints;
+
+monte(N,InCircle,NumPoints)->
+    Xcoord = rand:uniform(),
+    Ycoord = rand:uniform(),
+    monte(N-1,
+          if Xcoord*Xcoord + Ycoord*Ycoord < 1 -> InCircle + 1; true -> InCircle end,
+          NumPoints + 1).
+
+main(N) -> io:format("PI: ~w~n", [ monte(N) ]).

Task/Monte-Carlo-methods/Erlang/monte-carlo-methods-2.erl

@@ -0,0 +1,20 @@
+-module(monte2).
+-export([main/1]).
+
+monte(N)->
+    monte(N,0,0).
+
+monte(0,InCircle,NumPoints) ->
+    4 * InCircle / NumPoints;
+
+monte(N,InCircle,NumPoints)->
+    X = rand:uniform(),
+    Y = rand:uniform(),
+    monte(N-1, within(X,Y,InCircle), NumPoints + 1).
+
+within(X,Y,IN)->
+          if X*X + Y*Y < 1 -> IN + 1;
+          true -> IN
+          end.
+
+main(N) -> io:format("PI: ~w~n", [ monte(N) ]).