GS⁺ Autocorrelation Analysis

GS⁺ provides 11 different measures of autocorrelation, all accessible behind tabs in the same window. All analyses are straightforward: GS⁺ performs the analysis and immediately creates both isotropic (direction independent) and anisotropic (direction-dependent) variograms and correlograms.   Large data sets are no problem – GS⁺ allows an almost unlimited number of sample pairs within an almost unlimited number of lag class intervals (billions each), providing plenty of power and flexibility when you need it.
 

All analysis parameters have default values that can be changed and tested easily – making it easy for the novice to explore some of the underlying assumptions of various analyses.   Placing the mouse over a graphed point will produce a box showing the number of pairs in that lag class interval, and clicking on the point will produce a Variance Cloud graph or an h-Scattergram of all pairs in that interval. 

Semivariance analysis is displayed below. The variogram model (the line passing through the graphed semivariance values) is produced by GS⁺ using a nonlinear least squares algorithm; users can change the model and its parameters as they like by pressing the Model command, which brings up a Model Definition window. The Enlarge command brings up a separate Variogram window, and the Surface command brings up an Anisotropic Variogram Map window, useful for judging anisotropy and defining the appropriate axis orientation.