The G3GRID Procedure

Example 2: Spline and Smoothing Interpolations

Procedure features:

GRID statement options:

	SMOOTH=
	SPLINE

Data set:

NUMS (see Using the Default Interpolation Method)

Sample library member:

GTGSISS

This example extends Using the Default Interpolation Method to specify the SPLINE option on the GRID statement. The output data set, when used in PROC G3D, generates a smoother surface plot.

Surface Plot using Spline Interpolation (gtgsiss)

[A Surface Plot Generated After Spline Interpolation]

The following plot extends Using the Default Interpolation Method to specify the SPLINE option, and the SMOOTH= option on the GRID statement. The SMOOTH= option is set to .05 for additional smoothing. The output data set, when used in PROC G3D, generates a smoother surface plot.

Surface Plot using Spline Interpolation and .05 Smoothing (gtgsiss)

[A Surface Plot Generated After Smoothed Spline Interpolation]

goptions reset=all  border;

title "Surface Plot using Spline Interpolation";

proc g3grid data=nums out=spline;
   grid y*x=z / spline
                axis1=-5 to 5 by .5
                axis2=-5 to 5 by .5;
run;

proc g3d data=spline;
   plot y*x=z ;
run;
quit;

title "Surface Plot using Spline Interpolation and .05 Smoothing";

proc g3grid data=nums out=smoothed;
   grid y*x=z / spline
                smooth=.05
                axis1=-5 to 5 by .5
                axis2=-5 to 5 by .5;
run;
quit;

proc g3d data=smoothed;
   plot y*x=z;
run;
quit;

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