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 85.1 outlines the options available in PROC SIM2D classified by function.

Table 85.1: 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