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PopnStdDev function

In unit Math

Return Population standard deviation.

Declaration

pascal
function PopnStdDev(const data: Array of Single): Float

Description

Popnstddev returns the square root of the population variance of the values in the Data array. It returns zero if there is only one value.

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

Errors

None.

See also

Example: ex35

pascal
Program Example35;

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

Uses Math;

Type
  TExArray = Array[1..100] of Float;

Var
  I : Integer;
  ExArray : TExArray;

begin
  Randomize;
  for I:=low(ExArray) to high(ExArray) do
    ExArray[i]:=(Random-Random)*100;
  Writeln('Max              : ',MaxValue(ExArray):8:4);
  Writeln('Min              : ',MinValue(ExArray):8:4);
  Writeln('Pop. stddev.     : ',PopnStdDev(ExArray):8:4);
  Writeln('Pop. stddev. (b) : ',PopnStdDev(@ExArray[1],100):8:4);
end.

An experiment, built from development snapshots. Not the official Free Pascal or Lazarus documentation.