The VARIOGRAM Procedure

Overview

The VARIOGRAM procedure computes sample or empirical measures of spatial continuity for two-dimensional spatial data. These continuity measures are the regular semivariogram, a robust version of the semivariogram, and the covariance. The continuity measures are written to an output data set, allowing plotting or parameter estimation for theoretical semivariogram or covariance models. Both isotropic and anisotropic measures are available.

The VARIOGRAM procedure produces two additional output data sets that are useful in the analysis of pairwise distances in the original data. The OUTPAIR= data set contains one observation for each pair of points. The coordinates, distance, angle, and values of the analysis variables are written to this data set. The OUTDISTANCE= data set contains histogram information on the count of pairs within distance intervals, which is useful for determining unit lag distances.

Introduction to Spatial Prediction

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