[Overview][Constants][Types][Classes][Procedures and functions][Index] Reference for unit 'math' (#rtl)

stddev

Return standard deviation of data

Declaration

Source position: math.pp line 470

function stddev(

  const data: array of Single

):Float;

function stddev(

  const data: PSingle;

  const N: Integer

):Float;

function stddev(

  const data: array of Double

):Float;

function stddev(

  const data: PDouble;

  const N: Integer

):Float;

function stddev(

  const data: array of Extended

):Float;

function stddev(

  const data: PExtended;

  const N: Integer

):Float;

Description

Stddev returns the standard deviation of the values in Data. It returns zero if there is only one value.

The second form of the function accepts a pointer to an array of N values.

Errors

None.

See also

mean

  

Return mean value of array

meanandstddev

  

Return mean and standard deviation of array

variance

  

Return variance of values

totalvariance

  

Return total varians of values

Example

Program Example40;

{ Program to demonstrate the stddev function. }
{ @ should return typed pointer }
{$T+}

Uses Math;

Var
  I : Integer;
  ExArray : Array[1..10000] of Float;

begin
  Randomize;
  for I:=low(ExArray) to high(ExArray) do
    ExArray[i]:=Randg(1,0.2);
  Writeln('StdDev     : ',StdDev(ExArray):8:4);
  Writeln('StdDev (b) : ',StdDev(@ExArray[1],10000):8:4);
end.

Documentation generated on: Sep 28 2017