[GRASS-user] The r.neighbors algorithm

Hello, everyone:

I want to know the algorithm how to calculate r.neighbors (variance), I assuming it is the standard variance in the windows for replacing the focal value:

X^2 = sum(xi – xbar)^2 (I = 1, … 9 (3x3), or 25 (5x5), or 49 (7x7), or 81 (9x9), or 121(11x11), or etc).

Thanks for your further explanations

Qinglin