The SIM2D Procedure

Syntax: SIM2D Procedure

The following statements are available in the SIM2D procedure:

PROC SIM2D options;
BY variables;
COORDINATES coordinate-variables;
GRID grid-options;
ID variable;
RESTORE store-options;
SIMULATE simulate-options;
MEAN mean-options;

The SIMULATE and MEAN statements are hierarchical; you can specify any number of SIMULATE statements, but you must specify at least one. If you specify a MEAN statement, it refers to the preceding SIMULATE statement. If you omit the MEAN statement, a zero-mean model is simulated.

You must specify a single COORDINATES statement to identify the x and y coordinate variables in the input data set when you perform a conditional simulation. You must also specify a single GRID statement to specify the grid information.

Table 91.1 outlines the options available in PROC SIM2D classified by function.

Table 91.1: Options Available in the SIM2D Procedure

Task	Statement	Option
Data Set Options
Specify an input data set	PROC SIM2D	DATA=
Specify a grid data set	GRID	GDATA=
Specify labels for individual grid points or in 1-D	GRID	LABEL
Specify correlation model and parameters	SIMULATE	MDATA=
Write simulated values	PROC SIM2D	OUTSIM=
Specify plot display and options	PROC SIM2D	PLOTS
Specify a quadratic form data set	MEAN	QDATA=
Specify plot display and options	PROC SIM2D	PLOTS
Declaring the Role of Variables
Specify variables to define analysis subgroups	BY
Specify a variable with observation labels	ID
Specify the conditioning variable	SIMULATE	VAR=
Specify the x and y coordinate variables in the DATA= data set	COORDINATES	XC= YC=
Specify the x and y coordinate variables in the GDATA= data set	GRID	XC= YC=
Specify the constant coefficient variable in the QDATA= data set	MEAN	CONST=
Specify the linear x coefficient variable in the QDATA= data set	MEAN	CX=
Specify the linear y coefficient variable in the QDATA= data set	MEAN	CY=
Specify the quadratic x coefficient variable in the QDATA= data set	MEAN	CXX=
Specify the quadratic y coefficient variable in the QDATA= data set	MEAN	CYY=
Specify the quadratic $xy$ coefficient variable in the QDATA= data set	MEAN	CXY=
Controlling the Simulation
Specify the number of grid points in one-dimensional cases	GRID	NPTS=
Specify the number of realizations	SIMULATE	NUMREAL=
Specify the seed value for the random generator	SIMULATE	SEED=
Controlling the Mean Quadratic Surface
Specify the CONST term	MEAN	CONST=
Specify the linear x term	MEAN	CX=
Specify the linear y term	MEAN	CY=
Specify the quadratic x term	MEAN	CXX=
Specify the quadratic y term	MEAN	CYY=
Specify the quadratic cross term	MEAN	CXY=
Controlling the Semivariogram Model
Specify an angle for an anisotropic model	SIMULATE	ANGLE=
Specify nested angles	SIMULATE	ANGLE= ( $a_1,\cdots ,a_ k$ )
Specify a functional form	SIMULATE	FORM=
Specify nested functional forms	SIMULATE	FORM= ( $f_1,\cdots ,f_ k$ )
Specify a nugget effect	SIMULATE	NUGGET=
Specify a range parameter	SIMULATE	RANGE=
Specify nested range parameters	SIMULATE	RANGE= ( $r_1,\cdots ,r_ k$ )
Specify a minor-major axis ratio for an anisotropic model	SIMULATE	RATIO=
Specify nested minor-major axis ratios	SIMULATE	RATIO= ( $ra_1,\cdots ,ra_ k$ )
Specify a scale parameter	SIMULATE	SCALE=
Specify nested scale parameters	SIMULATE	SCALE= ( $s_1,\cdots ,s_ k$ )
Specify item store with correlation information	RESTORE	IN=
Specify model and parameters from an item store	SIMULATE	STORESELECT