Data commit

Task/Monte-Carlo-methods/Delphi/monte-carlo-methods.delphi

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+function MonteCarloPi(N: cardinal): double;
+{Approximate Pi by seeing if points fall inside circle}
+var I,InsideCnt: integer;
+var X,Y: double;
+begin
+InsideCnt:=0;
+for I:=1 to N do
+	begin
+	{Random X,Y = 0..1}
+	X:=Random;
+	Y:=Random;
+	{See if it falls in Unit Circle}
+	if X*X + Y*Y <= 1 then Inc(InsideCnt);
+	end;
+{Because X and Y are squared, they only fall with 1/4 of the circle}
+Result:=4 * InsideCnt / N;
+end;
+
+
+procedure ShowOneSimulation(Memo: TMemo; N: cardinal);
+var MyPi: double;
+begin
+MyPi:=MonteCarloPi(N);
+Memo.Lines.Add(Format('Samples: %15.0n   Pi= %2.15f',[N+0.0,MyPi]));
+end;
+
+
+procedure ShowMonteCarloPi(Memo: TMemo);
+begin
+ShowOneSimulation(Memo,1000);
+ShowOneSimulation(Memo,10000);
+ShowOneSimulation(Memo,100000);
+ShowOneSimulation(Memo,1000000);
+ShowOneSimulation(Memo,10000000);
+ShowOneSimulation(Memo,100000000);
+end;