Semivariance

As semivariance is referred to in the statistics half, middle, squared Euclidean distance between the measured values ​​z ( xi ) and z ( xi h ) at the locations xi and xi h for the distance or vector h

The term 1/2 [ z ( xi) - z ( xi h )] 2 is from a geometrical point of view nothing but the squared orthogonal distance of a point in the h- scatter plot of the diagonal y = x. A graph plotting the semi variance versus the distance h is referred to as a semi- variogram. From the model assumption of intrinsic stationarity follows that the semivariance an estimator of the variance of the increments halved Z ( xi h ) - Z ( xi).