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

variance

Return variance of values

Declaration

Source position: line 0

function variance(

  const data: array [] of float

):float;

function variance(

  const data: PFloat;

  const N: Integer

):float;

Description

Variancereturns the variance of the values in the dataarray. It returns zero if there is only one value.

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

Errors

None.

See also

totalvariance

  

Return total varians of values

stddev

  

Return standard deviation of data

mean

  

Return mean value of array

Example

Program Example50;

{ Program to demonstrate the Variance function. }

Uses math;

Var
  I : 1..100;
  ExArray : Array[1..100] of Float;
  V : float;

begin
  Randomize;
  for I:=low(ExArray) to high(ExArray) do
    ExArray[i]:=(Random-Random)*100;
  V:=Variance(ExArray);
  Writeln('Variance     : ',V:8:4);
  V:=Variance(@ExArray[1],100);
  Writeln('Variance (b) : ',V:8:4);
end.