The G3GRID Procedure

PROC G3GRID Statement

Identifies the input data set. Optionally specifies one or two output data sets.

Requirements: An input data set is required.

Syntax

PROC G3GRID <DATA=input-data-set>
<OUT=output-data-set>
<OUTTRI=output-data-set>;

Options

DATA=input-data-set

specifies the SAS data set that contains the variables to process. By default, the procedure uses the most recently created SAS data set.

OUT=output-data-set

specifies the output data set. The data set contains any BY variables that you specify, the interpolated or smoothed values of the vertical variables (z through z-n), and the coordinates for all grid positions on the horizontal (x-y) plane. If you specify smoothing, the output data set also contains a variable named _SMTH_, whose value is a smoothing parameter. The observations in this data set are ordered by any variables that you specify with a BY statement. By default, the output of PROC G3GRID creates WORK.DATA1.

Depending on the shape of the original data and the options you use, the output data set may contain values for the vertical (z through z-n) values that are outside of the range of the original values in the data set.

Featured in: Using the Default Interpolation Method

OUTTRI=output-data-set

specifies an additional output data set that contains triangular coordinates. The data set will contain any BY variables that you specify, the two horizontal variables giving the horizontal (x -y) plane coordinates of the input points, and a variable named TRIANGLE that uses integer values to label the triangles. The observations in this data set are ordered by any variables that you specify with a BY.

The data set contains three observations for each value of the variable TRIANGLE. The three observations give the coordinates of the three vertices of the triangle. Points on the convex hull of the input data set of points are also assumed to lie in degenerate triangles whose other vertices are at infinity. The points in the convex hull can be recovered by keeping only those triangles with exactly two missing vertices.

By default, no OUTTRI= data set is produced. OUTTRI= is not valid when you specify the SPLINE option in the GRID statement.

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