Declaration: MeanVarMatrixCircle (Data: TDouble2DArray; CentX, CentY, Radius: integer; var Mean, Variance: double): integer;
Calculates the mean and the variance of the data contained in the two-dimensional array Data, using all values in the circular region defined its center [CentX,CentY] and its radius given by the parameter Radius (the center coordinates and the radius are in pixels, the array Data has 0-based indices).

The function returns the following error codes:

 0 ... everything is OK
-1 ... CentX and/or CentY are out of range
-2 ... the Radius is less than 1

Last Update: 2017-Okt-30