Variogram itu apa sih? Jelaskan dalam bahasa sunda ya

Variogram (sacara téoritis)  nyaéta hiji fungsi nu ngajéntrékeun tingkat pakaitna spasial tina random field atawa stochastic process  spasial. It is defined as the expected squared increment of the values between locations  and  (Wackernagel 2003):

itself is called semivariogram. In case of a stationary process the variogram and semivariogram can be represented as a function  of the difference  between locations only, by the following relation (Cressie 1993):

If the process is furthermore isotropic, then variogram and semivariogram can be represented by a function  of the distance   only (Cressie 1993):

The indexes  or  are typically not written. The terms are used for all three forms of the function. Moréover the term variogram is sometimes used for semivariogram and the symbol  for the variogram, which brings some confusion.