TotalVariance
Return total variance of values
Declaration
Source position: math.pp line 526
function TotalVariance(const data: Array of Single) : Float;
function TotalVariance(const data: PSingle; const N: Integer) : Float;
function TotalVariance(const data: Array of Double) : Float;
function TotalVariance(const data: PDouble; const N: Integer) : Float;
function TotalVariance(const data: Array of Extended) : Float;
function TotalVariance(const data: PExtended; const N: Integer) : Float;
Description
TotalVariance returns the total variance of the values in the data array. 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
| Name | Description |
|---|---|
| mean | Return mean value of array |
| stddev | Return standard deviation of data |
| variance | Return variance of values |
Example
Program Example49;
{ Program to demonstrate the TotalVariance function. }
{ @ should return typed pointer }
{$T+}
Uses math;
Type
TExArray = Array[1..100] of Float;
Var
I : Integer;
ExArray : TExArray;
TV : float;
begin
Randomize;
for I:=1 to 100 do
ExArray[i]:=(Random-Random)*100;
TV:=TotalVariance(ExArray);
Writeln('Total variance : ',TV:8:4);
TV:=TotalVariance(@ExArray[1],100);
Writeln('Total Variance (b) : ',TV:8:4);
end.