The SAS Macros basically use the IML Procedure and GMAP and SQL Procedures. The computational implementation
of adaptive spatial sampling requires four steps: 1) development of the computational design of regular
grids (Figure 3(a)); 2) selection of specific areas of the grid, that is, identifying a sample and determining in which
part of the grid the data are located (Figure 3(b)); 3) identification of the neighbors of the selected areas: upper,
lower, right and left (Figure 3(c)(d)); 4) calculation of the parameters.