Cumulative standard deviation: Difference between revisions

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{{incomplete|Ada|It does not return the ''running'' standard deviation of the series.}}

<lang ada>with Ada.Numerics.Elementary_Functions; use Ada.Numerics.Elementary_Functions;

with Ada.Numerics.Elementary_Functions; use Ada.Numerics.Elementary_Functions;

with Ada.Text_IO; use Ada.Text_IO;

with Ada.Float_Text_IO; use Ada.Float_Text_IO;

with Ada.Integer_Text_IO; use Ada.Integer_Text_IO;

procedure Test_Deviation is

type Sample is record

N : Natural := 0;

~~Mean~~ : Float := 0.0;

Sum : Float := 0.0;

~~Squares~~ : Float := 0.0;

SumOfSquares : Float := 0.0;

end record;

procedure Add (Data : in out Sample; Point : Float) is

begin

Data.N := Data.N + 1;

Data.~~Mean~~ := Data.~~Mean~~ + Point;

Data.Sum := Data.Sum + Point;

Data.~~Squares~~ := Data.~~Squares~~ + Point ** 2;

Data.SumOfSquares := Data.SumOfSquares + Point ** 2;

end Add;

function Deviation (Data : Sample) return Float is

begin

return Sqrt (Data.~~Squares~~ / Float (Data.N) - (Data.~~Mean~~ / Float (Data.N)) ** 2);

return Sqrt (Data.SumOfSquares / Float (Data.N) - (Data.Sum / Float (Data.N)) ** 2);

end Deviation;

Data : Sample;

Test : array (1..8) of ~~Float~~ := (2.0, 4.0, 4.0, 4.0, 5.0, 5.0, 7.0, 9.0);

Test : array (1..8) of Integer := (2, 4, 4, 4, 5, 5, 7, 9);

begin

for ~~Item~~ in Test'Range loop

for Index in Test'Range loop

Add (Data, Test (~~Item~~));

Add (Data, Float(Test(Index)));

Put("N="); Put(Item => Index, Width => 1);

Put(" ITEM="); Put(Item => Test(Index), Width => 1);

Put(" AVG="); Put(Item => Float(Data.Sum)/Float(Index), Fore => 1, Aft => 3, Exp => 0);

Put(" STDDEV="); Put(Item => Deviation (Data), Fore => 1, Aft => 3, Exp => 0);

New_line;

end loop;

Put_Line ("Deviation" & Float'Image (Deviation (Data)));

end Test_Deviation;</lang>