The G3GRID procedure enables you to produce a data set with nonmissing values for z for every unique (x,y) combination. The output data set from the G3GRID procedure can be used as the input data set for the GCONTOUR procedure. The G3GRID procedure also enables you to smooth data for use with GCONTOUR. For details see G3GRID Procedure. For an interpolation example see Using the Default Interpolation Method.